xboard(6) GNU xboard(6)
$Date:
NAME
xboard - X graphical user interface for chess
SYNOPSIS
xboard [options]
xboard -ics -icshost hostname [options]
xboard -ncp [options]
|pxboard
cmail [options]
DESCRIPTION
XBoard is a graphical chessboard that can serve as a user interface to
chess engines (such as GNU Chess), the Internet Chess Servers,
electronic mail correspondence chess, or your own collection of saved
games.
This manual documents version 4.9.1 of XBoard.
MAJOR MODES
XBoard always runs in one of four major modes. You select the major
mode from the command line when you start up XBoard.
xboard [options]
As an interface to GNU Chess or another chess engine running on
your machine, XBoard lets you play a game against the machine,
set up arbitrary positions, force variations, watch a game
between two chess engines, interactively analyze your stored
games or set up and analyze arbitrary positions. To run engines
that use the UCI standard XBoard will draw upon the Polyglot
adapter fully transparently, but you will need to have the
polyglot package installed for this to work.
xboard -ics -icshost hostname [options]
As Internet Chess Server (ICS) interface, XBoard lets you play
against other ICS users, observe games they are playing, or
review games that have recently finished. Most of the ICS "wild"
chess variants are supported, including bughouse.
xboard -ncp [options]
XBoard can also be used simply as an electronic chessboard to
play through games. It will read and write game files and allow
you to play through variations manually. You can use it to browse
games off the net or review games you have saved. These features
are also available in the other modes.
|pxboard
If you want to pipe games into XBoard, use the supplied shell
script `pxboard'. For example, from the news reader `xrn', find
- 1 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
a message with one or more games in it, click the Save button,
and type `|pxboard' as the file name.
cmail [options]
As an interface to electronic mail correspondence chess, XBoard
works with the cmail program. See CMail below for instructions.
BASIC OPERATION
To move a piece, you can drag it with the left mouse button, or you
can click the left mouse button once on the piece, then once more on
the destination square. To under-promote a Pawn you can drag it
backwards until it morphs into the piece you want to promote to, after
which you drag that forward to the promotion square. Or after
selecting the pawn with a first click you can then click the promotion
square and move the mouse while keeping the button down until the
piece that you want appears in the promotion square. To castle you
move the King to its destination or, in Chess960, on top of the Rook
you want to castle with. In crazyhouse, bughouse or shogi you can
drag and drop pieces to the board from the holdings squares displayed
next to the board.
Old behavior, where right-clicking a square brings up a menu where you
can select what piece to drop on it can still be selected through the
`Drop Menu' option. Only in Edit Position mode right and middle
clicking a square is still used to put a piece on it, and the piece to
drop is selected by sweeping the mouse vertically with the button held
down.
The default function of the right mouse button in other modes is to
display the position the chess program thinks it will end up in.
While moving the mouse vertically with this button pressed XBoard will
step through the principal variation to show how this position will be
reached. Lines of play displayed in the engine-output window, or PGN
variations in the comment window can similarly be played out on the
board, by right-clicking on them. Only in Analysis mode, when you
walk along a PV, releasing the mouse button might forward the game
upto that point, like you entered all previous PV moves. As the
display of the PV in that case starts after the first move a simple
right-click will play the move the engine indicates.
In Analysis mode you can also make a move by grabbing the piece with a
double-click of the left mouse button (or while keeping the `Ctrl' key
pressed). In this case the move you enter will not be played, but
will be excluded from the analysis of the current position. (Or
included if it was already excluded; it is a toggle.) This only works
for engines that support this feature.
When connected to an ICS, it is possible to call up a graphical
representation of players seeking a game in stead of the chess board,
when the latter is not in use (i.e. when you are not playing or
observing). Left-clicking the display area will switch between this
- 2 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
'seek graph' and the chess board. Hovering the mouse pointer over a
dot will show the details of the seek ad in the message field above
the board. Left-clicking the dot will challenge that player. Right-
clicking a dot will 'push it to the back', to reveal any dots that
were hidden behind it. Right-clicking off dots will refresh the
graph.
Most other XBoard commands are available from the menu bar. The most
frequently used commands also have shortcut keys or on-screen buttons.
These shortcut keystrokes are mostly non-printable characters. Typing
a letter or digit while the board window has focus will bring up a
type-in box with the typed letter already in it. You can use that to
type a move in situations where it is your turn to enter a move, type
a move number to call up the position after that move in the display,
or, in Edit Position mode, type a FEN. Some rarely used parameters
can only be set through options on the command line used to invoke
XBoard.
XBoard uses a settings file, in which it can remember any changes to
the settings that are made through menus or command-line options, so
they will still apply when you restart XBoard for another session.
The settings can be saved into this file automatically when XBoard
exits, or on explicit request of the user. Note that the board window
can be sized by the user, but that this will not affect the size of
the clocks above it, and won't be remembered in the settings file. To
persistently change the size of the clocks, use the `size' command-
line option when starting XBoard. The default name for the settings
file is /etc/xboard/xboard.conf, but in a standard install this file
is only used as a master settings file that determines the system-wide
default settings, and defers reading and writing of user settings to a
user-specific file like ~/.xboardrc in the user's home directory.
When XBoard is iconized, its graphical icon is a white knight if it is
White's turn to move, a black knight if it is Black's turn.
MENUS, BUTTONS, AND KEYS
File Menu
New Game
Resets XBoard and the chess engine to the beginning of a new
chess game. The `Ctrl-N' key is a keyboard equivalent. In
Internet Chess Server mode, clears the current state of XBoard,
then resynchronizes with the ICS by sending a refresh command. If
you want to stop playing, observing, or examining an ICS game,
use an appropriate command from the Action menu, not `New Game'.
See Action Menu.
New Shuffle Game
Similar to `New Game', but allows you to specify a particular
initial position (according to a standardized numbering system)
in chess variants which use randomized opening positions (e.g.
- 3 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
Chess960).
shuffle
Ticking `shuffle' will cause the current variant to be played
with shuffled initial position. Shuffling will preserve the
possibility to castle in the way allowed by the variant.
Fischer castling
Ticking `Fischer castling' will allow castling with Kings and
Rooks that did not start in their normal place, as in Chess960.
Start-position number
randomize
pick fixed
The `Start-position number' selects a particular start position
from all allowed shufflings, which will then be used for every
new game. Setting this to -1 (which can be done by pressing the
`randomize' button) will cause a fresh random position to be
picked for every new game. Pressing the `pick fixed' button
causes `Start-position number' to be set to a random value, to be
used for all subsequent games.
New Variant
Allows you to select a new chess variant in non-ICS mode. (In ICS
play, the ICS is responsible for deciding which variant will be
played, and XBoard adapts automatically.) The shifted `Alt+V'
key is a keyboard equivalent. If you play with an engine, the
engine must be able to play the selected variant, or the
corresponding choice will be disabled. XBoard supports all major
variants, such as xiangqi, shogi, chess, chess960, makruk,
Capablanca Chess, shatranj, crazyhouse, bughouse.
You can overrule the default board format of the selected
variant, (e.g. to play suicide chess on a 6 x 6 board), in this
dialog, but normally you would not do that, and leave them at '-
1', which means 'default' for the chosen variant.
Load Game
Plays a game from a record file. The `Ctrl-O' key is a keyboard
equivalent. A pop-up dialog prompts you for the file name. If
the file contains more than one game, a second pop-up dialog
displays a list of games (with information drawn from their PGN
tags, if any), and you can select the one you want.
Alternatively, you can load the Nth game in the file directly, by
typing the number `N' after the file name, separated by a space.
The game-file parser will accept PGN (portable game notation), or
in fact almost any file that contains moves in algebraic
notation. Notation of the form `P@f7' is accepted for piece-drops
in bughouse games; this is a nonstandard extension to PGN. If
the file includes a PGN position (FEN tag), or an old-style
- 4 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
XBoard position diagram bracketed by `[--' and `--]' before the
first move, the game starts from that position. Text enclosed in
parentheses, square brackets, or curly braces is assumed to be
commentary and is displayed in a pop-up window. Any other text in
the file is ignored. PGN variations (enclosed in parentheses)
also are treated as comments; however, if you rights-click them
in the comment window, XBoard will shelve the current line, and
load the the selected variation, so you can step through it. You
can later revert to the previous line with the `Revert' command.
This way you can walk quite complex varation trees with XBoard.
The nonstandard PGN tag [Variant "varname"] functions similarly
to the -variant command-line option (see below), allowing games
in certain chess variants to be loaded. Note that it must appear
before any FEN tag for XBoard to recognize variant FENs
appropriately. There is also a heuristic to recognize chess
variants from the Event tag, by looking for the strings that the
Internet Chess Servers put there when saving variant ("wild")
games.
Load Position
Sets up a position from a position file. A pop-up dialog prompts
you for the file name. The shifted `Ctrl-O' key is a keyboard
equivalent. If the file contains more than one saved position,
and you want to load the Nth one, type the number N after the
file name, separated by a space. Position files must be in FEN
(Forsythe-Edwards notation), or in the format that the Save
Position command writes when oldSaveStyle is turned on.
Load Next Position
Loads the next position from the last position file you loaded.
The shifted `PgDn' key is a keyboard equivalent.
Load Previous Position
Loads the previous position from the last position file you
loaded. The shifted `PgUp' key is a keyboard equivalent. Not
available if the last position was loaded from a pipe.
Save Game
Appends a record of the current game to a file. The `Ctrl-S' key
is a keyboard equivalent. A pop-up dialog prompts you for the
file name. If the game did not begin with the standard starting
position, the game file includes the starting position used.
Games are saved in the PGN (portable game notation) format,
unless the oldSaveStyle option is true, in which case they are
saved in an older format that is specific to XBoard. Both formats
are human-readable, and both can be read back by the `Load Game'
command. Notation of the form `P@f7' is accepted for piece-drops
in bughouse games; this is a nonstandard extension to PGN.
Save Position
Appends a diagram of the current position to a file. The shifted
- 5 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
`Ctrl+S' key is a keyboard equivalent. A pop-up dialog prompts
you for the file name. Positions are saved in FEN (Forsythe-
Edwards notation) format unless the `oldSaveStyle' option is
true, in which case they are saved in an older, human-readable
format that is specific to XBoard. Both formats can be read back
by the `Load Position' command.
Save Selected Games
Will cause all games selected for display in the current Game
List to be appended to a file of the user's choice.
Save Games as Book
Creates an opening book from the currently loaded game file,
incorporating only the games currently selected in the Game List.
The book will be saved on the file specified in the `Common
Engine' options dialog. The value of `Book Depth' specified in
that same dialog will be used to determine how many moves of each
game will be added to the internal book buffer. This command can
take a long time to process, and the size of the buffer is
currently limited. At the end the buffer will be saved as a
Polyglot book, but the buffer will not be cleared, so that you
can continue adding games from other game files.
Mail Move
Reload CMail Message
See CMail.
Exit Exits from XBoard. The `Ctrl-Q' key is a keyboard equivalent.
Edit Menu
Copy Game
Copies a record of the current game to an internal clipboard in
PGN format and sets the X selection to the game text. The `Ctrl-
C' key is a keyboard equivalent. The game can be pasted to
another application (such as a text editor or another copy of
XBoard) using that application's paste command. In many X
applications, such as xterm and emacs, the middle mouse button
can be used for pasting; in XBoard, you must use the Paste Game
command.
Copy Position
Copies the current position to an internal clipboard in FEN
format and sets the X selection to the position text. The shifted
`Ctrl-C' key is a keyboard equivalent. The position can be
pasted to another application (such as a text editor or another
copy of XBoard) using that application's paste command. In many
X applications, such as xterm and emacs, the middle mouse button
can be used for pasting; in XBoard, you must use the Paste
Position command.
- 6 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
Copy Game List
Copies the current game list to the clipboard, and sets the X
selection to this text. A format of comma-separated double-
quoted strings is used, including all tags, so it can be easily
imported into spread-sheet programs.
Paste Game
Interprets the current X selection as a game record and loads it,
as with Load Game. The `Ctrl-V' key is a keyboard equivalent.
Paste Position
Interprets the current X selection as a FEN position and loads
it, as with Load Position. The shifted `Ctrl-V' key is a keyboard
equivalent.
Edit Game
Allows you to make moves for both Black and White, and to change
moves after backing up with the `Backward' command. The clocks do
not run. The `Ctrl-E' key is a keyboard equivalent.
In chess engine mode, the chess engine continues to check moves
for legality but does not participate in the game. You can bring
the chess engine into the game by selecting `Machine White',
`Machine Black', or `Two Machines'.
In ICS mode, the moves are not sent to the ICS: `Edit Game' takes
XBoard out of ICS Client mode and lets you edit games locally.
If you want to edit games on ICS in a way that other ICS users
can see, use the ICS `examine' command or start an ICS match
against yourself.
Edit Position
Lets you set up an arbitrary board position. The shifted `Ctrl-
E' key is a keyboard equivalent. Use mouse button 1 to drag
pieces to new squares, or to delete a piece by dragging it off
the board or dragging an empty square on top of it. When you do
this keeping the `Ctrl' key pressed, or start dragging with a
double-click, you will move a copy of the piece, leaving the
piece itself where it was. In variants where pieces can promote
(such as Shogi), left-clicking an already selected piece promotes
or demotes it. To drop a new piece on a square, press mouse
button 2 or 3 over the square. This puts a white or black pawn
in the square, respectively, but you can change that to any other
piece type by dragging the mouse down before you release the
button. You will then see the piece on the originally clicked
square cycle through the available pieces (including those of
opposite color), and can release the button when you see the
piece you want. (Note you can swap the function of button 2 and
3 by pressing the shift key, and that there is an option
`monoMouse' to combine al functions in one button, which then
acts as button 3 over an empty square, and as button 1 over a
- 7 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
piece.) To alter the side to move, you can click the clock (the
words White and Black above the board) of the side you want to
give the move to. To clear the board you can click the clock of
the side that already has the move (which is highlighted in
black). If you repeat this the board will cycle from empty to a
`pallette board' containing every piece once to the initial
position to the one before clearing. The quickest way to set up
a position is usually to start with the pallette board, and move
the pieces to were you want them, duplicating them where
necessary by using the `Ctrl' key, dragging those you don't want
off board, and use static button 2 or 3 clicks to place the
Pawns. The old behavior with a piece menu can still be
configured with the aid of the `pieceMenu' option. Dragging
empty squares off board can create boards with holes
(inaccessible black squares) in them. Selecting `Edit Position'
causes XBoard to discard all remembered moves in the current
game.
In ICS mode, changes made to the position by `Edit Position' are
not sent to the ICS: `Edit Position' takes XBoard out of `ICS
Client' mode and lets you edit positions locally. If you want to
edit positions on ICS in a way that other ICS users can see, use
the ICS `examine' command, or start an ICS match against
yourself. (See also the ICS Client topic above.)
Edit Tags
Lets you edit the PGN (portable game notation) tags for the
current game. After editing, the tags must still conform to the
PGN tag syntax:
<tag-section> ::= <tag-pair> <tag-section>
<empty>
<tag-pair> ::= [ <tag-name> <tag-value> ]
<tag-name> ::= <identifier>
<tag-value> ::= <string>
See the PGN Standard for full details. Here is an example:
[Event "Portoroz Interzonal"]
[Site "Portoroz, Yugoslavia"]
[Date "1958.08.16"]
[Round "8"]
[White "Robert J. Fischer"]
[Black "Bent Larsen"]
[Result "1-0"]
Any characters that do not match this syntax are silently
ignored. Note that the PGN standard requires all games to have at
least the seven tags shown above. Any that you omit will be
filled in by XBoard with `?' (unknown value), or `-'
(inapplicable value).
- 8 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
Edit Comment
Adds or modifies a comment on the current position. Comments are
saved by `Save Game' and are displayed by `Load Game', PGN
variations will also be printed in this window, and can be
promoted to main line by right-clicking them. `Forward', and
`Backward'.
Edit Book
Pops up a window listing the moves available in the GUI book
(specified in the `Common Engine Settings' dialog) from the
currently displayed position, together with their weights and
(optionally in braces) learn info. You can then edit this list,
and the new list will be stored back into the book when you press
'save changes'. When you press the button 'add next move', and
play a move on the board, that move will be added to the list
with weight 1. Note that the listed percentages are neither
used, nor updated when you change the weights; they are just
there as an optical aid. When you right-click a move in the list
it will be played.
Revert
Annotate
If you are examining an ICS game and Pause mode is off, Revert
issues the ICS command `revert'. In local mode, when you were
editing or analyzing a game, and the `-variations' command-line
option is switched on, you can start a new variation by holding
the Shift key down while entering a move not at the end of the
game. Variations can also become the currently displayed line by
clicking a PGN variation displayed in the Comment window. This
can be applied recursively, so that you can analyze variations on
variations; each time you create a new variation by entering an
alternative move with Shift pressed, or select a new one from the
Comment window, the current variation will be shelved. `Revert'
allows you to return to the most recently shelved variation. The
difference between `Revert' and `Annotate' is that with the
latter, the variation you are now abandoning will be added as a
comment (in PGN variation syntax, i.e. between parentheses) to
the original move where you deviated, for later recalling. The
`Home' key is a keyboard equivalent to `Revert'.
Truncate Game
Discards all remembered moves of the game beyond the current
position. Puts XBoard into `Edit Game' mode if it was not there
already. The `End' key is a keyboard equivalent.
Backward
< Steps backward through a series of remembered moves. The `[<]'
button and the `Alt+LeftArrow' key are equivalents, as is turning
the mouse wheel towards you. In addition, pressing the ??? key
steps back one move, and releasing it steps forward again.
- 9 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
In most modes, `Backward' only lets you look back at old
positions; it does not retract moves. This is the case if you are
playing against a chess engine, playing or observing a game on an
ICS, or loading a game. If you select `Backward' in any of these
situations, you will not be allowed to make a different move. Use
`Retract Move' or `Edit Game' if you want to change past moves.
If you are examining an ICS game, the behavior of `Backward'
depends on whether XBoard is in Pause mode. If Pause mode is off,
`Backward' issues the ICS backward command, which backs up
everyone's view of the game and allows you to make a different
move. If Pause mode is on, `Backward' only backs up your local
view.
Forward
> Steps forward through a series of remembered moves (undoing the
effect of `Backward') or forward through a game file. The `[>]'
button and the `Alt+RightArrow' key are equivalents, as is
turning the mouse wheel away from you.
If you are examining an ICS game, the behavior of Forward depends
on whether XBoard is in Pause mode. If Pause mode is off,
`Forward' issues the ICS forward command, which moves everyone's
view of the game forward along the current line. If Pause mode is
on, `Forward' only moves your local view forward, and it will not
go past the position that the game was in when you paused.
Back to Start
<< Jumps backward to the first remembered position in the game. The
`[<<]' button and the `Alt+Home' key are equivalents.
In most modes, Back to Start only lets you look back at old
positions; it does not retract moves. This is the case if you are
playing against a local chess engine, playing or observing a game
on a chess server, or loading a game. If you select `Back to
Start' in any of these situations, you will not be allowed to
make different moves. Use `Retract Move' or `Edit Game' if you
want to change past moves; or use Reset to start a new game.
If you are examining an ICS game, the behavior of @samp{Back to
Start} depends on whether XBoard is in Pause mode. If Pause mode
is off, `Back to Start' issues the ICS `backward 999999' command,
which backs up everyone's view of the game to the start and
allows you to make different moves. If Pause mode is on,
@samp{Back to Start} only backs up your local view.
Forward to End
>> Jumps forward to the last remembered position in the game. The
`[>>]' button and the `Alt+End' key are equivalents.
If you are examining an ICS game, the behavior of @samp{Forward
- 10 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
to End} depends on whether XBoard is in Pause mode. If Pause mode
is off, `Forward to End' issues the ICS `forward 999999' command,
which moves everyone's view of the game forward to the end of the
current line. If Pause mode is on, `Forward to End' only moves
your local view forward, and it will not go past the position
that the game was in when you paused.
View Menu
Flip View
Inverts your view of the chess board for the duration of the
current game. Starting a new game returns the board to normal.
The `F2' key is a keyboard equivalent.
Show Engine Output
Shows or hides a window in which the thinking output of any
loaded engines is displayed. The shifted `Alt+O' key is a
keyboard equivalent. XBoard will display lines of thinking
output of the same depth ordered by score, (highest score on
top), rather than in the order the engine produced them. Usually
this amounts to the same, as a normal engine search will only
find new PV (and emit it as thinking output) when it searches a
move with a higher score than the previous variation. But when
the engine is in multi-variation mode this needs not always be
true, and it is more convenient for someone analyzing games to
see the moves sorted by score. The order in which the engine
found them is only of interest to the engine author, and can
still be deduced from the time or node count printed with the
line. Right-clicking a line in this window, and then moving the
mouse vertically with the right button kept down, will make
XBoard play through the PV listed there. The use of the board
window as 'variation board' will normally end when you release
the right button, or when the opponent plays a move. But beware:
in Analysis mode, moves thus played out might be added to the
game, depending on the setting of the option 'Play moves of
clicked PV', when you initiate the click left of the PV in the
score area. The Engine-Output pane for each engine will contain
a header displaying the multi-PV status and a list of excluded
moves in Analysis mode, which are also responsive to right-
clicking: Clicking the words 'fewer' or 'more' will alter the
number of variations shown at each depth, through the engine's
MultiPV option, while clicking in between those and moving the
mouse horizontally adjust the option 'Multi-PV Margin'. (In so
far the engines support those.)
Show Move History
Shows or hides a list of moves of the current game. The shifted
`Alt+H' key is a keyboard equivalent. This list allows you to
move the display to any earlier position in the game by clicking
on the corresponding move.
- 11 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
Show Evaluation Graph
Shows or hides a window which displays a graph of how the engine
score(s) evolved as a function of the move number. The shifted
`Alt+E' key is a keyboard equivalent. The title bar shows the
score (and search depth at which it was obtained) of the
currently displayed position numerically. Clicking on the graph
will bring the corresponding position in the board display. A
button 3 click will toggle the display mode between plain and
differential (showing the difference in score between successive
half moves). Using the mouse wheel over the window will change
the scale of the low-score region (from -1 to +1).
Show Game List
Shows or hides the list of games generated by the last `Load
Game' command. The shifted `Alt+G' key is a keyboard equivalent.
The line describing each game is built from a selection of the
PGN tags. Which tags contribute, and in what order, can be
changed by the `Game list tags' menu dialog, which can be popped
up through the `Tags' button below the Game List. Display can be
restricted to a sub-set of the games meeting certain criteria. A
text entry below the game list allows you to type a text that the
game lines must contain in order to be displayed. Games can also
be selected based on their Elo PGN tag, as set in the `Load Game
Options' dialog, which can be popped up through the `Thresholds'
button below the Game List. Finally they can be selected based
on containing a position similar to the one currently displayed
in the main window, by pressing the 'Position' button below the
Game List, (which searches the entire list for the position), or
the 'Narrow' button (which only searches the already-selected
games). What counts as similar enough to be selected can also be
set in the `Load Game Options' dialog, and ranges from an exact
match to just the same material.
Tags Pops up a window which shows the PGN (portable game notation)
tags for the current game. For now this is a duplicate of the
`Edit Tags' item in the `Edit' menu.
Comments
Pops up a window which shows any comments to or variations on the
current move. For now this is a duplicate of the `Edit Comment'
item in the `Edit' menu.
ICS Input Box
If this option is set in ICS mode, XBoard creates an extra window
that you can use for typing in ICS commands. The input box is
especially useful if you want to type in something long or do
some editing on your input, because output from ICS doesn't get
mixed in with your typing as it would in the main terminal
window.
- 12 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
ICS/Chat Console
This menu item opens a window in which you can interact with the
ICS, so you don't have to use the messy xterm from which you
launched XBoard for that. The window has a text entry at the
bottom where you can type your commands and messages unhindered
by the stream of ICS output. The latter will be displayed in a
large pane above the input field, the ICS Console. Up and down
arrow keys can be used to recall previous input lines. Typing an
<Esc> character in the input field transfers focus back to the
board window (so you could operate the menus there through
accelerator keys). Typing a printable character in the board
window transfers focus back to the input field of the `ICS
Chat/Console' window.
Chats
There is a row of buttons at the top of the `ICS Chat/Console'
dialog, which can be used to navigate between upto 5 'chats' with
other ICS users (or channels). These will switch the window to
'chat mode', where the ICS output pane is vertically split to
divert messages from a specific user or ICS channel to the lower
half. Lines typed in the input field will then be interpreted as
messages to be sent to that user or channel, (automatically
prefixed with the apporpriate ICS command and user name) rather
than as commands to the ICS. Chats will keep collecting ICS
output intended for them even when not displayed, and their
buttons will turn orange to alert the user there has been
activity. Typing <Tab> in the input field will switch to another
active chat, giving priority to those with content you have not
seen yet.
New Chat
Buttons for chats currently not assigned to a user or channel
will carry the text `New Chat', and pressing them will switch to
chat mode, enabling you to enter the user name or channel number
you want to use it for. Typing Ctrl-N in the input field is a
keyboard equivalent.
Chat partner
To (re-)assign a chat, write the name of your chat partner, the
channel number, or the words 'shouts', 'whispers', 'cshouts' in
the `Chat partner' text entry (ending with <Enter>!). Typing
Ctrl-O in the input field at the bottom of the window will open a
chat with the person that last sent you a 'tell' that was printed
in the ICS Console output pane. The `ICS text menu' can contain
a button `Open Chat (name)' that can be used to open a chat with
as partner the word/number you right-clicked in the output pane
to pop up this menu.
End Chat
This button, only visible when the chat pane is open, will clear
the `Chat partner' field, so that the chat can be assigned to a
- 13 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
new user or channel. Typing Ctrl-E in the input field is a
keyboard equivalent.
Hide This button, only visible when the chat pane is open, will close
the latter, so you can use the input field to give commands to
the ICS again. Typing Ctrl-H in the input field is a keyboard
equivalent.
ICS text menu
Brings up a menu that is user-configurable through the `icsMenu'
option. Buttons in this menu can sent pre-configured commands
directly to the ICS, or can put partial commands in the input
field of the `ICS Chat/Console' window, so that you can complete
those with some text of your own before sending them to the ICS
by pressing Enter. This menu item can also be popped up by
right-clicking in the text memos of the ICS Chat/Console window.
In that case the word that was clicked can be incorporated in the
message sent to the ICS. E.g. to challenge a player whose name
you click for a game, or prepare for sending him a message
through a 'tell' commands.
Edit ICS menu
Brings up an edit box with the definition of the `ICS text menu',
so you can adapt its appearance to your needs. The menu is
defined by a semi-colon-separated list, each button through a
pair of items in it. The first item of each pair is the text on
the button, the second the text to be sent when the button is
pressed. The word '$input' in the text will put that text in the
input field of the `ICS Chat/Console' with the cursor in that
place, the word '$name' will be replaced by the word right-
clicked to pop up the text menu.
Edit Theme List
Brings up an edit box with the definitions of the themes shown in
the listbox of the `Board' dialog, so you can delete, re-order or
alter themes defined previously.
Board
Summons a dialog where you can customize the look of the chess
board.
White Piece Color
Black Piece Color
Light Square Color
Dark Square Color
Highlight Color
Premove Highlight Color
These items set the color of pieces, board squares and move
highlights (borders or arrow). Square colors are only used when
the `Use Board Textures' option is off, the piece colors only
when `Use piece bitmaps with their own colors' is off. You can
- 14 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
type the color as hexadecimally encoded RGB value preceded by
'#', or adjust it through the R, G, B and D buttons to make it
redder, greener, bluer or darker. A sample of the adjusted color
will be displayed behind its text description; pressing this
colored button restores the default value for the color.
Flip Pieces Shogi Style
With this option on XBoard will swap white and black pieces, when
you flip the view of the board to make white play downward. This
should be used with piece themes that do not distinguish sides by
color, but by orientation.
Mono Mode
This option sets XBoard to pure black-and-white display (no grey
scales, and thus no anti-aliasing).
Logo Size
Specifies the width of the engine logos displayed next to the
clocks, in pixels. Setting it to 0 suppresses the display of
such logos. The height of the logo will be half its width. In
the GTK build of XBoard any non-zero value is equivalent, and the
logos are always sized to 1/4 of the board width.
Line Gap
This option specifies the width of the grid lines that separate
the squares, which change color on highlighting the move.
Setting it to 0 suppresses these lines, which in general looks
better, but hides the square-border highlights, so that you would
have to rely on other forms of highlighting. Setting the value
to -1 makes XBoard choose a width by itself, depending on the
square size.
Use Board Textures
Light-Squares Texture File
Dark-Squares Texture File
When the option `Use Board Textures' is set, the squares will not
be drawn as evenly colored surfaces, but will be cut from a
texture image, as specified by the `Texture Files'. Separate
images can be used for light and dark squares. XBoard will try
to cut the squares out of the texture image with as little
overlap as possible, so they all look different. The name of the
texture file can contain a size hint, e.g. `xqboard-9x10.png',
alerting XBoard to the fact that it contains a whole-board image,
out of which squares have to be cut in register with the nominal
sub-division.
Use external piece bitmaps with their
When this option is on XBoard will ignore the piece-color
settings, and draw the piece images in their original colors.
The piece-color settings would only work well for evenly colored
pieces, such as the default theme.
- 15 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
Directory with Pieces Images
When a directory is specified here, XBoard will first look for
piece images (SVG or PNG files) in that directory, and fall back
on the image from the default theme only for images it cannot
find there. An image file called White/BlackTile in the
directory will be prefered as fall-back for missing pieces over
the default image, however.
Selectable themes
New name for current theme
When a theme name is specified while pressing 'OK', the
combination of settings specified in the dialog will be stored in
XBoard's list of themes, which will be saved with the other
options in the settings file (as the `themeNames' option). This
name will then appear in the selection listbox next time you open
the dialog, so that you can recall the entire combination of
settings by double-clicking it.
Here you can specify the directory from which piece images should
be taken, when you don't want to use the built-in piece images
(see `pieceImageDirectory' option), external images to be used
for the board squares (`liteBackTextureFile' and
`darkBackTextureFile' options), and square and piece colors for
the default pieces. The current combination of these settings
can be assigned a 'theme' name by typing one in the text entry in
the lower-left of the dialog, and closing the latter with OK. It
will then appear in the themes listbox next time you open the
dialog, where you can recall the complete settings combination
with a double-click.
Fonts
Pops up a dialog where you can set the fonts used in the main
elements of various windows. Pango font names can be typed for
each window type, and behind each text entry there are buttons to
adjust the point size, and toggle the 'bold' or 'italic'
attributes of the font.
Game List Tags
a duplicate of the Game List dialog in the Options menu.
Mode Menu
Machine White
Tells the chess engine to play White. The `Ctrl-W' key is a
keyboard equivalent.
Machine Black
Tells the chess engine to play Black. The `Ctrl-B' key is a
keyboard equivalent.
Two Machines
Plays a game between two chess engines. The `Ctrl-T' key is a
- 16 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
keyboard equivalent.
Analysis Mode
XBoard tells the chess engine to start analyzing the current
game/position and shows you the analysis as you move pieces
around. The `Ctrl-A' key is a keyboard equivalent. Note: Some
chess engines do not support Analysis mode.
To set up a position to analyze, you do the following:
1. Set up the position by any means. (E.g. using `Edit Position'
mode, pasing a FEN or loading a game and stepping to the
position.)
2. Select Analysis Mode from the Mode Menu to start the analysis.
You can now play legal moves to create follow-up positions for
the engine to analyze, while the moves will be remembered as a
stored game, and then step backward through this game to take the
moves back. Note that you can also click on the clocks to set
the opposite side to move (adding a so-called `null move' to the
game).
You can also tell the engine to exclude some moves from analysis.
(Engines that do not support the exclude-moves feature will
ignore this, however.) The general way to do this is to play the
move you want to exclude starting with a double click on the
piece. When you use drag-drop moving, the piece you grab with a
double click will also remain on its square, to show you that you
are not really making the move, but just forbid it from the
current position. Playing a thus excluded move a second time
will include it again. Excluded moves will be listed as text in
a header line in the Engine Output window, and you can also re-
include them by right-clicking them there. This header line will
also contain the words 'best' and 'tail'; right-clicking those
will exclude the currently best move, or all moves not explicitly
listed in the header line. Once you leave the current position
all memory of excluded moves will be lost when you return there.
Selecting this menu item while already in `Analysis Mode' will
toggle the participation of the second engine in the analysis.
The output of this engine will then be shown in the lower pane of
the Engine Output window. The analysis function can also be used
when observing games on an ICS with an engine loaded (zippy
mode); the engine then will analyze the positions as they occur
in the observed game.
Analyze Game
This option subjects the currently loaded game to automatic
analysis by the loaded engine. The `Ctrl-G' key is a keyboard
- 17 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
equivalent. XBoard will start auto-playing the game from the
currently displayed position, while the engine is analyzing the
current position. The game will be annotated with the results of
these analyses. In particlar, the score and depth will be added
as a comment, and the PV will be added as a variation.
Normally the analysis would stop after reaching the end of the
game. But when a game is loaded from a multi-game file while
`Analyze Game' was already switched on, the analysis will
continue with the next game in the file until the end of the file
is reached (or you switch to another mode).
The time the engine spends on analyzing each move can be
controlled through the command-line option `-timeDelay', which
can also be set from the `Load Game Options' menu dialog. Note:
Some chess engines do not support Analysis mode.
Edit Game
Duplicate of the item in the Edit menu. Note that `Edit Game' is
the idle mode of XBoard, and can be used to get you out of other
modes. E.g. to stop analyzing, stop a game between two engines or
stop editing a position.
Edit Position
Duplicate of the item in the Edit menu.
Training
Training mode lets you interactively guess the moves of a game
for one of the players. You guess the next move of the game by
playing the move on the board. If the move played matches the
next move of the game, the move is accepted and the opponent's
response is auto-played. If the move played is incorrect, an
error message is displayed. You can select this mode only while
loading a game (that is, after selecting `Load Game' from the
File menu). While XBoard is in `Training' mode, the navigation
buttons are disabled.
ICS Client
This is the normal mode when XBoard is connected to a chess
server. If you have moved into Edit Game or Edit Position mode,
you can select this option to get out.
To use xboard in ICS mode, run it in the foreground with the -ics
option, and use the terminal you started it from to type commands
and receive text responses from the chess server. See Chess
Servers below for more information.
XBoard activates some special position/game editing features when
you use the `examine' or `bsetup' commands on ICS and you have
`ICS Client' selected on the Mode menu. First, you can issue the
ICS position-editing commands with the mouse. Move pieces by
- 18 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
dragging with mouse button 1. To drop a new piece on a square,
press mouse button 2 or 3 over the square. This brings up a menu
of white pieces (button 2) or black pieces (button 3).
Additional menu choices let you empty the square or clear the
board. Click on the White or Black clock to set the side to
play. You cannot set the side to play or drag pieces to
arbitrary squares while examining on ICC, but you can do so in
`bsetup' mode on FICS. In addition, the menu commands `Forward',
`Backward', `Pause', and `Stop Examining' have special functions
in this mode; see below.
Machine Match
Starts a match between two chess programs, with a number of games
and other parameters set through the `Tournament Options' menu
dialog. When a match is already running, selecting this item
will make XBoard drop out of match mode after the current game
finishes.
Pause
Pauses updates to the board, and if you are playing against a
chess engine, also pauses your clock. To continue, select `Pause'
again, and the display will automatically update to the latest
position. The `P' button and keyboard `Pause' key are
equivalents.
If you select Pause when you are playing against a chess engine
and it is not your move, the chess engine's clock will continue
to run and it will eventually make a move, at which point both
clocks will stop. Since board updates are paused, however, you
will not see the move until you exit from Pause mode (or select
Forward). This behavior is meant to simulate adjournment with a
sealed move.
If you select Pause while you are observing or examining a game
on a chess server, you can step backward and forward in the
current history of the examined game without affecting the other
observers and examiners, and without having your display jump
forward to the latest position each time a move is made. Select
Pause again to reconnect yourself to the current state of the
game on ICS.
If you select `Pause' while you are loading a game, the game
stops loading. You can load more moves manually by selecting
`Forward', or resume automatic loading by selecting `Pause'
again.
Action Menu
Accept
Accepts a pending match offer. The `F3' key is a keyboard
equivalent. If there is more than one offer pending, you will
have to type in a more specific command instead of using this
- 19 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
menu choice.
Decline
Declines a pending offer (match, draw, adjourn, etc.). The `F4'
key is a keyboard equivalent. If there is more than one offer
pending, you will have to type in a more specific command instead
of using this menu choice.
Call Flag
Calls your opponent's flag, claiming a win on time, or claiming a
draw if you are both out of time. The `F5' key is a keyboard
equivalent. You can also call your opponent's flag by clicking
on his clock.
Draw Offers a draw to your opponent, accepts a pending draw offer from
your opponent, or claims a draw by repetition or the 50-move
rule, as appropriate. The `F6' key is a keyboard equivalent.
Adjourn
Asks your opponent to agree to adjourning the current game, or
agrees to a pending adjournment offer from your opponent. The
`F7' key is a keyboard equivalent.
Abort
Asks your opponent to agree to aborting the current game, or
agrees to a pending abort offer from your opponent. The `F8' key
is a keyboard equivalent. An aborted game ends immediately
without affecting either player's rating.
Resign
Resigns the game to your opponent. The `F9' key is a keyboard
equivalent.
Stop Observing
Ends your participation in observing a game, by issuing the ICS
observe command with no arguments. ICS mode only. The `F10' key
is a keyboard equivalent.
Stop Examining
Ends your participation in examining a game, by issuing the ICS
unexamine command. ICS mode only. The `F11' key is a keyboard
equivalent.
Upload to Examine
Create an examined game of the proper variant on the ICS, and
send the game there that is currenty loaded in XBoard (e.g.
through pasting or loading from file). You must be connected to
an ICS for this to work.
Adjudicate to White
- 20 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
Adjudicate to Black
Adjudicate Draw
Terminate an ongoing game in Two-Machines mode (including match
mode), with as result a win for white, for black, or a draw,
respectively. The PGN file of the game will accompany the result
string by the comment "user adjudication".
Engine Menu
Edit Engine List
Opens a window that shows the list of engines registered for use
by XBoard, together with the options that would be used with them
when you would select them from the `Load Engine' dialogs. You
can then edit this list, e.g. for re-ordering the engines, or
adding uncommon options needed by this engine (e.g. to cure non-
compliant behavior).
By editing you can also organize the engines into collapsible
groups. By sandwiching a number of engine lines between lines "#
NAME" and "# end", the thus enclosed engines will not initially
appear in engine listboxes of other dialogs, but only the single
line "# NAME" (where NAME can be an arbitrary text) will appear
in their place. Selecting that line will then show the enclosed
engines in the listbox, which recursively can contain other
groups. The line with the group name will still present as a
header, and selecting that line will collapse the group again,
and makes the listbox go back to displaying the surrounding
group.
Load New 1st Engine
Load New 2nd Engine
Pops up a dialog where you can select or specify an engine to be
loaded. You can even replace engines during a game, without
disturbing that game. (Beware that after loading an engine,
XBoard will always be in Edit Game mode, so you will have to tell
the new engine what to do before it does anything!)
Select engine from list
The listbox shows the engines registered for use with XBoard
before. (This means XBoard has information on the engine type,
whether it plays book etc. in the engine list stored in its
settings file.) Double-clicking an engine here will load it and
close the dialog. The list can also contain groups, indicated by
a starting '#' sign. Double-clicking such a group will 'open'
it, and show the group contents in the listbox instead of the
total list, with the group name as header. Double-clicking the
header will 'close' the group again.
Nickname
Use nickname in PGN player tags
When a `Nickname' is specified, the engine will appear under this
name in the `Select Engine' listbox. Otherwise the name there
- 21 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
will be a tidied version of the engine command. The user can
specify if the nickname is also to be used in PGN tags; normally
the name engines report theselves would be used there.
Engine Command
The command needed to start the engine from the command line.
For compliantly installed engine this is usually just a single
word, the name of the engine package (e.g. 'crafty' or
'stockfish'). Some engines need additional parameters on the
command line. For engines that are not in a place where the
system would expect them a full pathname can be specified, and
usually the browse button for this oprion is the easiest way to
obtain that.
Engine Directory
Compliant engines could run from any directory, and by default
this option is proposed as '.', the current directory. If a
(path)name is specified here, XBoard will start the engine in
that directory. If you make the field empty, it will try to
derive the directory from the engine command (if that was a path
name).
UCI When the `UCI' checkbox is ticked XBoard will assume the engine
is of UCI type, and will invoke the corresponding adapter (as
specified in the `adapterCommand' option stored in its settings
file)to use it. By default this adapter is Polyglot, which must
be installed from a separate package!
USI/UCCI
Ticking this checkbox informs XBoard that the engine is of USI or
UCCI type (as Shogi or Xiangqi engines often are). This makes
XBoard invoke an adapter to run the engines, as specified by the
`uxiAdapter' option stored in its settings file. The UCI2WB
program is an adapter that can handle both these engine types, as
well as UCI.
WB protocol v1
Ticking this checkbox informs XBoard the engine is using an old
version (1) of the communication protocol, so that it won't
respond to a request to interrogate its properties. XBoard then
won't even try that, saving you a wait of several seconds each
time the engine is started. Do not use this on state-of-the-art
engines, as it would prevent XBoard from interrogating its
capabilities, so that many of its features might not work!
Must not use GUI book
By default XBoard assumes engines are responsible for their own
opening book, but unticking this option makes XBoard consult its
own book (as per `Opening-Book Filename') on behalf of the
engine.
- 22 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
Add this engine to the list
By default XBoard would add the engine you specified, with all
the given options to its list of registered engines (kept in its
settings file), when you press 'OK'. Next time you could then
simply select it from the listbox, or use the command "xboard -fe
NICKNAME" to start XBoard with the engine and accompanying
options. New engines are always added at the end of the existing
list, or, when you have opened a group in the `Select Engine'
listbox, at the end of that group. But can be re-ordered later
with the aid of the `Edit Engine List' menu item. When you
untick this checkbox before pressing 'OK' the engine will be
loaded, but will not be added to the engine list.
Force current variant with this engine
Ticking this option will make XBoard automatically start the
engine in the current variant, even when XBoard was set for a
different variant when you loaded the engine. Useful when the
engine plays multiple variants, and you specifically want to play
one different from its primary one.
Engine #1 Settings
Engine #2 Settings
Pop up a menu dialog to alter the settings specific to the
applicable engine. For each parameter the engine allows to be
set, a control element will appear in this dialog that can be
used to alter the value. Depending on the type of parameter
(text string, number, multiple choice, on/off switch,
instantaneous signal) the appropriate control will appear, with a
description next to it. XBoard has no idea what these values
mean; it just passes them on to the engine. How this dialog
looks is completely determined by the engine, and XBoard just
passes it on to the user. Many engines do not have any
parameters that can be set by the user, and in that case the
dialog will be empty (except for the OK and cancel buttons). UCI
engines usually have many parameters. (But these are only visible
with a sufficiently modern version of the Polyglot adapter needed
to run UCI engines, e.g. Polyglot 2.0.1.) For native XBoard
engines this is less common.
Common Settings
Pops up a menu dialog where you can set some engine parameters
common to most engines, such as hash-table size, tablebase cache
size, maximum number of processors that SMP engines can use. The
shifted `Alt+U' key is a keyboard equivalent. Older
XBoard/WinBoard engines might not respond to these settings, but
UCI engines always should.
Maximum Number of CPUs per Engine
Specifies the number of search threads any engine can maximally
use. Do not set it to a number larger than the number of cores
- 23 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
your computer has. (Or half of it when you want two engines to
run simultaneously, as in a Two-Machines game with `Ponder Next
Move' on.)
Polyglot Directory
Hash-Table Size
Specifies the maximum amount of memory (RAM) each engine is
allowed to use for storing info on positions it already searched,
so it would not have to search them again. Do not set it so that
it is more than half (or if you use two engines, more than a
quarter) of the memory your computer has, or it would slow the
engines down by an extreme amount.
EGTB Path
Sets the value of the `egtFormats' option, which specifies where
on your computer the files for End-Game Tables are stored. It
must be a comma-separated list of path names, the path for each
EGT flavor prefixed with the name of the latter and a colon. E.g.
"nalimov:/home/egt/dtm,syzygy:/home/egt/dtz50". The path names
after the colon will be sent to the engines that say they can use
the corresponding EGT flavor.
EGTB Cache Size
Specifies the amount of memory the engine should use to buffer
end-game information. Together with the `Hash-Table Size' this
determines how much memory the engine is allowed to use in total.
Use GUI Book
Opening-Book Filename
The `Opening-Book Filename' specifies an opening book in Polyglot
format (usually a .bin file), from which XBoard can play moves on
behalf of the engine. This is also the book file on which the
`Edit Book' and `Save Games as Book' menu items operate. A
checkbox `Use GUI Book' can be used to temporarily disable the
book without losing the setting. (This does not prevent editing
or saving games on it!)
Book Depth
Book Variety
The way moves are selected from the book can be controlled by two
options. `Book Depth' controls for how deep into the game the
book will be consulted (measured in full moves). `Book Variety'
controls the likelihood of playing weaker moves. When the
variety is set to 50, moves will be played with the probability
specified in the book. When set to 0, only the move(s) with the
highest probability will be played. When set to 100, all listed
moves will be played with equal pobability. Other settings
interpolate between that.
- 24 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
Engine #1 Has Own Book
Engine #2 Has Own Book
These checkboxes control on a per-engine basis whether XBoard
will consult the opening book for them. If ticked, XBoard will
never play moves from its GUI book, giving the engine the
opportunity to use its own. These options are automatically set
whenever you load an engine, based on the setting of `Must not
use GUI book' when you installed that through the `Load Engine'
menu dialog.
Hint Displays a move hint from the chess engine.
Book Displays a list of possible moves from the chess engine's opening
book. The exact format depends on what chess engine you are
using. With GNU Chess 4, the first column gives moves, the
second column gives one possible response for each move, and the
third column shows the number of lines in the book that include
the move from the first column. If you select this option and
nothing happens, the chess engine is out of its book or does not
support this feature.
Move Now
Forces the chess engine to move immediately. Chess engine mode
only. The `Ctrl-M' key is a keyboard equivalent. Many engines
won't respond to this.
Retract Move
Retracts your last move. In chess engine mode, you can do this
only after the chess engine has replied to your move; if the
chess engine is still thinking, use `Move Now' first. In ICS
mode, `Retract Move' issues the command `takeback 1' or `takeback
2' depending on whether it is your opponent's move or yours. The
`Ctrl-X' key is a keyboard equivalent.
Recently Used Engines
At the bottom of the engine menu there can be a list of names of
engines that you recently loaded through the Load Engine menu
dialog in previous sessions. Clicking on such a name will load
that engine as first engine, so you won't have to search for it
in your list of installed engines, if that is very long. The
maximum number of displayed engine names is set by the
`recentEngines' command-line option.
Options Menu
Mute all Sounds
Ticking this menu item toggles all sounds XBoard can make on or off,
without losing their definitions.
General Options
The following items to set option values appear in the dialog summoned
by the general Options menu item.
- 25 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
Absolute Analysis Scores
Controls if scores on the Engine Output window during analysis
will be printed from the white or the side-to-move point-of-view.
Almost Always Queen
If this option is on, 7th-rank pawns automatically change into
Queens when you pick them up, and when you drag them to the
promotion square and release them there, they will promote to
that. But when you drag such a pawn backwards first, its
identity will start to cycle through the other available pieces.
This will continue until you start to move it forward; at which
point the identity of the piece will be fixed, so that you can
safely put it down on the promotion square. If this option is
off, what happens depends on the option `alwaysPromoteToQueen',
which would force promotion to Queen when true. Otherwise XBoard
would bring up a dialog box whenever you move a pawn to the last
rank, asking what piece you want to promote to.
Animate Dragging
If Animate Dragging is on, while you are dragging a piece with
the mouse, an image of the piece follows the mouse cursor. If
Animate Dragging is off, there is no visual feedback while you
are dragging a piece, but if Animate Moving is on, the move will
be animated when it is complete.
Animate Moving
If Animate Moving is on, all piece moves are animated. An image
of the piece is shown moving from the old square to the new
square when the move is completed (unless the move was already
animated by Animate Dragging). If Animate Moving is off, a moved
piece instantly disappears from its old square and reappears on
its new square when the move is complete. The shifted `Ctrl-A'
key is a keyboard equivalent.
Auto Flag
If this option is on and one player runs out of time before the
other, XBoard will automatically call his flag, claiming a win on
time. The shifted `Ctrl-F' key is a keyboard equivalent. In ICS
mode, Auto Flag will only call your opponent's flag, not yours,
and the ICS may award you a draw instead of a win if you have
insufficient mating material. In local chess engine mode, XBoard
may call either player's flag.
Auto Flip View
If the Auto Flip View option is on when you start a game, the
board will be automatically oriented so that your pawns move from
the bottom of the window towards the top.
If you are playing a game on an ICS, the board is always oriented
at the start of the game so that your pawns move from the bottom
of the window towards the top. Otherwise, the starting
- 26 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
orientation is determined by the `flipView' command line option;
if it is false (the default), White's pawns move from bottom to
top at the start of each game; if it is true, Black's pawns move
from bottom to top. See User interface options.
Blindfold
If this option is on, XBoard displays the board as usual but does
not display pieces or move highlights. You can still move in the
usual way (with the mouse or by typing moves in ICS mode), even
though the pieces are invisible.
Drop Menu
Controls if right-clicking the board in crazyhouse / bughouse
will pop up a menu to drop a piece on the clicked square (old,
deprecated behavior) or allow you to step through an engine PV
(new, recommended behavior).
Enable Variation Trees
If this option is on, playing a move in Edit Game or Analyze mode
while keeping the Shift key pressed will start a new variation.
You can then recall the previous line through the `Revert' menu
item. When off, playing a move will truncate the game and append
the move irreversibly.
Headers in Engine Output Window
Controls the presence of column headers above the variations and
associated information printed by the engine, on which you can
issue button 3 clicks to open or close the columns. Available
columns are search depth, score, node count, time used, tablebase
hits, search speed and selective search depth.
Hide Thinking
If this option is off, the chess engine's notion of the score and
best line of play from the current position is displayed as it is
thinking. The score indicates how many pawns ahead (or if
negative, behind) the chess engine thinks it is. In matches
between two machines, the score is prefixed by `W' or `B' to
indicate whether it is showing White's thinking or Black's, and
only the thinking of the engine that is on move is shown. The
shifted `Ctrl-H' key is a keyboard equivalent.
Highlight Last Move
If Highlight Last Move is on, after a move is made, the starting
and ending squares remain highlighted. In addition, after you use
Backward or Back to Start, the starting and ending squares of the
last move to be unmade are highlighted.
Highlight with Arrow
Causes the highlighting described in Highlight Last Move to be
done by drawing an arrow between the highlighted squares, so that
it is visible even when the width of the grid lines is set to
- 27 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
zero.
One-Click Moving
If this option is on, XBoard does not wait for you to click both
the from- and the to-square, or drag the piece, but performs a
move as soon as it is uniqely specified. This applies to
clicking an own piece that only has a single legal move, clicking
an empty square or opponent piece where only one of your pieces
can move (or capture) to. Furthermore, a double-click on a piece
that can only make a single capture will cause that capture to be
made. Promoting a Pawn by clicking its to-square will suppress
the promotion popup or other methods for selecting an under-
promotion, and make it promote to Queen.
Periodic Updates
If this option is off (or if you are using a chess engine that
does not support periodic updates), the analysis window will only
be updated when the analysis changes. If this option is on, the
Analysis Window will be updated every two seconds.
Play Move(s) of Clicked PV
If this option is on, right-clicking on the first move of a PV or
on the data fields left of it in the Engine Output window during
Analyze mode will cause the first move of that PV to be played.
You could also play more than one (or no) PV move by moving the
mouse to engage in the PV walk such a right-click will start, to
seek out another position along the PV where you want to continue
the analysis, before releasing the mouse button. Clicking on
later moves of the PV only temporarily show the moves for as long
you keep the mouse button down, without adding them to the game.
Ponder Next Move
If this option is off, the chess engine will think only when it
is on move. If the option is on, the engine will also think
while waiting for you to make your move. The shifted `Ctrl-P'
key is a keyboard equivalent.
Popup Exit Message
If this option is on, when XBoard wants to display a message just
before exiting, it brings up a modal dialog box and waits for you
to click OK before exiting. If the option is off, XBoard prints
the message to standard error (the terminal) and exits
immediately.
Popup Move Errors
If this option is off, when you make an error in moving (such as
attempting an illegal move or moving the wrong color piece), the
error message is displayed in the message area. If the option is
on, move errors are displayed in small pop-up windows like other
errors. You can dismiss an error pop-up either by clicking its
OK button or by clicking anywhere on the board, including down-
- 28 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
clicking to start a move.
Scores in Move List
If this option is on, XBoard will display the depth and score of
engine moves in the Move List, in the format of a PGN comment.
Show Coords
If this option is on, XBoard displays algebraic coordinates along
the board's left and bottom edges.
Show Target Squares
If this option is on, all squares a piece that is 'picked up'
with the mouse can legally move to are highighted with a fat
colored dot in yellow (non-captures) or red (captures). Special
moves might have other colors (e.g. magenta for promotion, cyan
for a partial move). Legality testing must be on for XBoard to
know how the piece moves, but with legality testing off some
engines would offer this information.
Sticky Windows
Controls whether the auxiliary windows such as Engine Output,
Move History and Evaluation Graph should keep touching XBoard's
main window when you move the latter.
Test Legality
If this option is on, XBoard tests whether the moves you try to
make with the mouse are legal and refuses to let you make an
illegal move. The shifted `Ctrl-L' key is a keyboard equivalent.
Moves loaded from a file with `Load Game' are also checked. If
the option is off, all moves are accepted, but if a local chess
engine or the ICS is active, they will still reject illegal
moves. Turning off this option is useful if you are playing a
chess variant with rules that XBoard does not understand.
(Bughouse, suicide, and wild variants where the king may castle
after starting on the d file are generally supported with Test
Legality on.)
Top-Level Dialogs
Controls whether the auxiliary windows will appear as icons in
the task bar and independently controllable, or whether they open
and minimize all together with the main window.
Flash Moves
Flash Rate
If this option is non-zero, whenever a move is completed, the
moved piece flashes the specified number of times. The flash-
rate setting determines how rapidly this flashing occurs.
Animation Speed
Determines the duration (in msec) of an animation step, when
`Animate Moving' is swiched on.
- 29 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
Zoom factor in Evaluation Graph
Sets the value of the `evalZoom' option, indicating the factor by
which the score interval (-1,1) should be blown up on the
vertical axis of the Evaluation Graph.
Time Control
Pops up a sub-menu where you can set the time-control parameters
interactively. The shifted `Alt+T' key is a keyboard equivalent.
classical
Selects classical TC, where the game is devided into sessions of
a certain number of moves, and after each session the start time
is again added to the clocks.
incremental
Selects a TC mode where the game will start with a base time on
the clocks, and after every move an 'increment' will be added to
it.
fixed max
Selects a TC mode where you have to make each move within a given
time, and any left-over time is not carried over to the next
move.
Divide entered times by 60
To allow entering of sub-minute initial time or sub-second
increment, you can tick this checkbox. The initial time can then
be entered in seconds, and the increment in units of 1/60 second.
Moves per session
Sets the duration of a session for classical time control.
Initial time
Time initially on the clock in classical or incremental time
controls. In classical time controls this time will also be
added to the clock at the start of ach new session.
Increment or max
Time to be added to the clock after every move in incremental TC
mode. Fore 'fixed maximum' TC mode, the clock will be set to
this time before every move, irrespective of how much was left on
that clock.
Time-Odds factors
When these options are set to 1 the clocks of the players will be
set according to the other specified TC parameters. Players can
be given unequal times by specifying a time-odds factor for one
of them (or a different factor for both of them). Any time
received by that player will then be divided by that factor.
- 30 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
Adjudications
Pops up a sub-menu where you can enable or disable various
adjudications that XBoard can perform in engine-engine games. The
shifted `Alt+J' key is a keyboard equivalent.
Detect all Mates
When this option is set XBoard will terminate the game on
checkmate or stalemate, even if the engines would not do so.
Only works when `Test Legality' is on.
Verify Engine Result Claims
When this option is set XBoard will verify engine result claims,
(forfeiting engines that make false claims), rather than naively
beleiving the engine. Only works when `Test Legality' is on.
Draw if Insufficient Mating Material
When this option is set XBoard will terminate games with a draw
result when so little material is left that checkmate is not
longer possible. In normal Chess this applies to KK, KNK, KBK
and some positions with multiple Bishops all on the same square
shade. Only works when `Test Legality' is on.
Adjudicate Trivial Draws
When this option is set XBoard will terminate games with a draw
result in positions that could only be won against an idiot. In
normal Chess this applies to KNNK, KRKR, KBKN, KNKN, and KBKB
with Bishops on different square shades. KQKQ will also be
adjudicated a draw (possibly unjustly so). Only works when `Test
Legality' is on.
N-Move Rule
When this option is set to a value differnt from zero XBoard will
terminate games with a draw result after the specified number of
reversible moves (i.e. without captures or pawn pushes) is made.
N-fold Repeats
When this option is set to a value larger than 1, XBoard will
terminate games with a draw result when the same position has
occurred the specified number of times.
Draw after N Moves Total
When this option is set to a value different from zero, XBoard
will terminate games with a draw result after that many moves
have been played. Useful in automated engine-engine matches, to
prevent one game between stubborn engines will soak up all your
computer time.
Win / Loss Threshold
When this option is set to a value different from zero, XBoard
will terminate games as a win when both engines agree the score
is above the specified value (interpreted as centi-Pawn) for
- 31 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
three successive moves.
Negate Score of Engine #1
Negate Score of Engine #2
These options should be used with engines that report scores from
the white point of view, rather than the side-to-move POV as
XBoard would otherwise assume when adjudicating games based on
the engine score. When the engine is installed with the extra
option `firstScoreIsAbs' true in the engine list the option would
be automatically set when the engine is loaded throuhgh the
Engine menu, or with the `fe' or `se' command-line option.
ICS Options
Pops up a menu dialog where options can be set that affect playing
against an Internet Chess Server.
Auto-Kibitz
Setting this option when playing with or aginst a chess program
on an ICS will cause the last line of thinking output of the
engine before its move to be sent to the ICS in a kibitz command.
In addition, any kibitz message received through the ICS from an
opponent chess program will be diverted to the engine-output
window, (and suppressed in the console), where you can play
through its PV by right-clicking it.
Auto-Comment
If this option is on, any remarks made on ICS while you are
observing or playing a game are recorded as a comment on the
current move. This includes remarks made with the ICS commands
`say', `tell', `whisper', and `kibitz'. Limitation: remarks that
you type yourself are not recognized; XBoard scans only the
output from ICS, not the input you type to it.
Auto-Observe
If this option is on and you add a player to your `gnotify' list
on ICS, XBoard will automatically observe all of that player's
games, unless you are doing something else (such as observing or
playing a game of your own) when one starts. The games are
displayed from the point of view of the player on your gnotify
list; that is, his pawns move from the bottom of the window
towards the top. Exceptions: If both players in a game are on
your gnotify list, if your ICS `highlight' variable is set to 0,
or if the ICS you are using does not properly support observing
from Black's point of view, you will see the game from White's
point of view.
Auto-Raise Board
If this option is on, whenever a new game begins, the chessboard
window is deiconized (if necessary) and raised to the top of the
stack of windows.
- 32 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
Auto Save
If this option is true, at the end of every game XBoard prompts
you for a file name and appends a record of the game to the file
you specify. Disabled if the `saveGameFile' command-line option
is set, as in that case all games are saved to the specified
file. See Load and Save options.
Background Observe while Playing
Setting this option will make XBoard suppress display of any
boards from observed games while you are playing. Instead the
last such board will be remembered, and shown to you when you
right-click the board. This allows you to peek at your bughouse
partner's game when you want, without disturbing your own game
too much.
Dual Board for Background-Observed Game
Setting this option in combination with `Background Observe' will
display boards of observed games while you are playing on a
second board next to that of your own game.
Get Move List
If this option is on, whenever XBoard receives the first board of
a new ICS game (or a different game from the one it is currently
displaying), it retrieves the list of past moves from the ICS.
You can then review the moves with the `Forward' and `Backward'
commands or save them with `Save Game'. You might want to turn
off this option if you are observing several blitz games at once,
to keep from wasting time and network bandwidth fetching the move
lists over and over. When you turn this option on from the menu,
XBoard immediately fetches the move list of the current game (if
any).
Quiet Play
If this option is on, XBoard will automatically issue an ICS `set
shout 0' command whenever you start a game and a `set shout 1'
command whenever you finish one. Thus, you will not be
distracted by shouts from other ICS users while playing.
Seek Graph
Setting this option will cause XBoard to display an graph of
currently active seek ads when you left-click the board while
idle and logged on to an ICS.
Auto-Refresh Seek Graph
In combination with the `Seek Graph' option this will cause
automatic update of the seek graph while it is up. This only
works on FICS and ICC, and requires a lot of bandwidth on a busy
server.
Auto-InputBox PopUp
Controls whether the ICS Input Box will pop up automatically when
- 33 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
you type a printable character to the board window in ICS mode.
Quit After Game
Controls whether XBoard will automatically disconnect from the
ICS and close when the game currently in progress finishes.
Premove
Premove for White
Premove for Black
First White Move
First Black Move
If the `Premove' option is on while playing a game on an ICS, you
can register your next planned move before it is your turn. Move
the piece with the mouse in the ordinary way, and the starting
and ending squares will be highlighted with a special color (red
by default). When it is your turn, if your registered move is
legal, XBoard will send it to ICS immediately; if not, it will be
ignored and you can make a different move. If you change your
mind about your premove, either make a different move, or
double-click on any piece to cancel the move entirely.
You can also enter premoves for the first white and black moves
of the game.
Alarm
Alarm Time
When this option is on, an alarm sound is played when your clock
counts down to the `Alarm Time' in an ICS game. (By default, the
time is 5 seconds, but you can specify other values with the
Alarm Time spin control.) For games with time controls that
include an increment, the alarm will sound each time the clock
counts down to the icsAlarmTime. By default, the alarm sound is
the terminal bell, but on some systems you can change it to a
sound file using the soundIcsAlarm option; see below.
Colorize Messages
Ticking this options causes various types of ICS messages do be
displayed with different foreground or background colors in the
console. The colors can be individually selected for each type,
through the accompanying text edits.
-icsMenu string
The string defines buttons for the `ICS text menu'. Each button
definition consists of two semi-colon-terminated pieces of text,
the first giving the label to be written on the button, the
second the text that should be sent to the ICS when that button
is pressed. This second part (the 'message') can contain
linefeeds, so that you can send multiple ICS commands with one
button. Some message in the text, all starting with a $-sign,
are treated special. When the message contains '$input', it will
not be sent directly to the ICS, but will be put in the input
- 34 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
field of the `ICS Chat/Console', with the text cursor at the
indicated place, so you can addsome text to the message before
sending it off. If such a message starts with '$add' it will be
placed behind any text that is already present in the input
field, otherwise this field will be cleared first. The word
'$name' occurring in the message will be replaced by the word
that was clicked (through button 3) in the ICS Chat/Console.
There are two special messages: '$chat' will open a new chat with
the clicked word in the chat-partner field, while '$copy' will
copy the text that is currently-selected in the ICS Console to
the clipboard. An example of a text menu as it might occur in
your settings file (where you could edit it):
-icsMenu {copy;$copy;
list players;who;
list games;games;
finger (player);finger $name;
bullet (player);match $name 1 1 r;
blitz (player);match $name 5 1 r;
rapid (player);match $name 30 0 r;
open chat (player);$chat;
tell (player);tell $name $input;
ask pieces;ptell Please give me a $input;
P;$add Pawn $input;
N;$add Knight $input;
B;$add Bishop $input;
R;$add Rook $input;
Q;$add Queen $input;
}
Tournament Options
Summons a dialog where you can set options important for playing
automatic matches between two or more chess programs (e.g. by using
the `Machine Match' menu item in the `Mode' menu).
Tournament file
To run a tournament, XBoard needs a file to record its progress,
so it can resume the tourney when it is interrupted. When you
want to conduct anything more complex than a simple two-player
match with the currently loaded engines, (i.e. when you select a
list of participants), you must not leave this field blank. When
you enter the name of an existing tournament file, XBoard will
ignore all other input specified in the dialog, and will take the
corresponding info from that tournament file. This resumes an
interrupted tournament, or adds another XBoard agent playing
games for it to those that are already doing so. Specifying a
not-yet-existing file will cause XBoard to create it, according
to the tournament parameters specified in the rest of the dialog,
before it starts the tournament on OK. Provided that you
specify participants; without participants no tournament file
will be made, but other entered values (e.g. for the file with
- 35 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
opening positions) will take effect. Default: configured by the
`defaultTourneyName' option.
Sync after round
Sync after cycle
The sync options, when on, will cause WinBoard to refrain from
starting games of the next round or cycle before all games of the
previous round or cycle are finished. This guarantees correct
ordering in the games file, even when multiple XBoard instances
are concurrently playing games for the same tourney. Default:
sync after cycle, but not after round.
Select Engine
Tourney participants
From the Select Engine listbox you can pick an engine from your
list of engines registered in the settings file, to be added to
the tournament. The engines selected so far will be listed in
the Tourney participants memo. The latter is a normal text
edit, so you can use normal text-editing functions to delete
engines you selected accidentally, or change their order. Typing
names here yourself is not recommended, because names that do not
exactly match one of the names from the selection listbox will
lead to undefined behavior.
Tourney type
Here you can specify the type of tournament you want. XBoards
intrinsic tournament manager support round-robins (type = 0),
where each participant plays every other participant, and
(multi-)gauntlets, where one (or a few) so-called gauntlet
engines play an independent set of opponents. In the latter
case, you specify the number of gauntlet engines. E.g. if you
specified 10 engines, and tourney type = 2, the first 2 engines
each play the remaining 8. A value of -1 instructs XBoard to play
Swiss; for this to work an external pairing engine must be
specified through the `pairingEngine' option. Each Swiss round
will be considered a tourney cycle in that case. Default:0
Number of tourney cycles
Default Number of Games in Match
You can specify tourneys where every two opponents play each
other multiple times. Such multiple games can be played in a row,
as specified by the number of games per pairing, or by
repeating the entire tournament schedule a number of times
(specified by the number of tourney cycles). The total
number of times two engines meet will be the product of these
two. Default is 1 cycle; the number of games per pairing is the
same as the default number of match games, stored in your
settings file through the `defaultMatchGames' option.
Pause between Match Games
Time (in milliseconds) XBoard waits before starting a new game
- 36 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
after a previous match or tournament game finishes. Such a
waiting period is important for engines that do not support
'ping', as these sometimes still produce a move long after the
game finished because of the opponent resigning, which would be
mistaken for a move in the next game if that had already started.
Save Tourney Games on
File where the tournament games are saved (duplicate of the item
in the `Save Game Options').
Game File with Opening Lines
File with Start Positions
Game Number
Position Number
Rewind Index after this many Games
These items optionally specify the file with move sequences or
board positions the tourney games should start from. The
corresponding numbers specify the number of the game or position
in the file. Here a value -1 means automatic stepping through
all games on the file, -2 automatic stepping every two games.
The Rewind-Index parameter causes a stepping index to reset to
one after reaching a specified value. A setting of -2 for the
game number will also be effective in a tournament without
specifying a game file, but playing from the GUI book instead.
In this case the first (odd) games will randomly select from the
book, but the second (even) games will select the same moves from
the book as the previous game. (Note this leads to the same
opening only if both engines use the GUI book!) Default: No game
or position file will be used. The default index if such a file
is used is 1.
Disable own engine books by default
Setting this option reverses the default situation for use of the
GUI opening book in tournaments from what it normally is, namely
not using it. So unless the engine is installed with an option
to explicitly specify it should not use the GUI book (i.e. `-
firstHasOwnBookUCI true'), it will be made to use the GUI book.
Replace Engine
Upgrade Engine
With these two buttons you can alter the participants of an
already running tournament. After opening the Match Options
dialog on an XBoard that is playing for the tourney, you will see
all the tourney parameters in the dialog fields. You can then
replace the name of one engine by that of another by editing the
`participants' field. (But preserve the order of the others!)
Pressing the button after that will cause the substitution. With
the `Upgrade Engine' button the substitution will only affect
future games. With `Replace Engine' all games the substituted
engine has already played will be invalidated, and they will be
replayed with the substitute engine. In this latter case the
- 37 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
engine must not be playing when you do this, but otherwise there
is no need to pause the tournament play for making a
substitution.
Clone Tourney
Pressing this button after you have specified an existing
tournament file will copy the contents of the latter to the
dialog, and then puts the originally proposed name for the
tourney file back. You can then run a tourney with the same
parameters (possibly after changing the proposed name of the
tourney file for the new tourney) by pressing 'OK'.
Continue Later
Pressing the `Continue Later' button confirms the current value
of all items in the dialog and closes it, but will not
automatically start the tournament. This allows you to return to
the dialog later without losing the settings you already entered,
to adjust paramenters through other menu dialogs. (The `Common
Engine Setting', `Time Control' and `General Options' dialogs can
be accessed without closing the `Tournament Options' dialog
through the respective buttons at the bottom of the latter.)
Load Game Options
Summons a dialog where you can set options that control loading of
games.
Auto-Display Tags
Setting this option causes a window to pop up on loading a game,
displaying the PGN Tags for that game.
Auto-Display Comment
Setting this option causes a window to pop up whenever there is a
comment to (or variation on) the currently displayed move.
Auto-Play speed of loaded games
This option sets the number of seconds between moves when a newly
loaded game is auto-playing. A decimal fraction on the number is
understood. Setting it to -1 disables auto-play, staying in the
start position of the game after the loading completes. Setting
it to 0 will instantly move to the final position of the game.
The `Auto-Play speed' is also used to determine the analysis time
for each move during `Analyze Game'. Note that auto-playing
(including game analysis) can be stopped at any time through the
`P' button above the board.
options to use in game-viewer mode
Specifies the options automatically set when XBoard is invoked
with the option `-viewer' on its command line, as will happen
when it is started in response to clicking a PGN game file. The
default setting would start XBoard without engine (due to the `-
ncp' option), but if you want it to automatically start with your
- 38 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
favorite engine, and automatically start analyzing, you could
include the necessary options for that here (e.g. `-fe <engine>
-initialMode analysis').
Thresholds for position filtering in game
The following options can be set to limit the display of games in
the `Game List' window to a sub-set, meeting the specified
criteria.
Elo of strongest player at least
Elo of weakest player at least
Games with an Elo tag specifying a lower rating for the mentioned
player will not be diplayed in the `Game List'.
No games before year
Games with a Date tag before the specified year will not be
diplayed in the `Game List'.
Final nr of pieces
A single number or a range (like 8-10) can be entered here, and
will cause only games where the number of men in the final
position is in the given range will be diplayed in the `Game
List'.
Minimum nr consecutive positions
Specifies for how many consecutive positions the more fuzzy
position-matching criteria have to be satisfied in order to count
as a match.
Search mode
find position
XBoard can select games for display in the `Game List' based on
whether (in addition to the conditions on the PGN tags) they
contain a position that matches the position currently displayed
on the board, by pressing the `find position' or `narrow' buttons
in the `Game List' window. The `Search mode' setting determines
what counts as match. You can search for an exact match, a
position that has all shown material in the same place, but might
contain additional material, a position that has all Pawns in the
same place, but can have the shown material anywhere, a position
that can have all shown material anywhere, or a position that
has material between certain limits anywhere. For the latter you
have to place the material that must minimally be present in the
four lowest ranks of the board, and optional additional material
in the four highest ranks of the board. You can request the
optional material to be balanced, i.e. equal for white and black.
narrow
The `narrow' button is similar in fuction to the `find position'
button, but only searches in the already selected games, rather
- 39 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
than the complete game file, and can thus be used to refine a
search based on multiple criteria.
Also match reversed colors
Also match left-right flipped position
When looking for matching positions rather than by material,
these settings determine whether mirror images (in case of a
vertical flip in combination with color reversal) will be also
considered a match. The left-right flipping is only useful after
all castling rights have expired (or in Xiangqi).
Save Game Options
Summons a dialog where you can specify whether XBoard should
automatically save files of games when they finish, and where and how
to do that.
Auto-Save Games
When set XBoard will automatically save games on a file as they
finish. (Not when you abort them by pressing `New Game',
though!) It will either prompt you for a filename, or use the
file specified by the `saveGameFile' option.
Own Games Only
Setting this option will exclude games by others observed on an
Internet Chess Server from automatic saving.
Save Games on File
Name of the file on which games should be saved automatically.
Games are always appended to the file, and will never overwrite
anything.
Save Final Position on File
When a name is defined, the final position of each game is
appended to the mentioned file.
PGN Event Header
Specifies the name of the event used in the PGN event tag of new
games that you create.
Old Save Style
Saves games in an obsolete and now long forgotten format, rather
than as PGN. Never use this for orthodox Chess!
Include Number Tag in tourney PGN
When on this option will cause the non-standard 'Number' tag to
be written in any game saved in PGN format. It will contain the
unique number of the game in the tourney. (As opposed to the
'Round' tag, which can be shared by many games.)
Save Score/Depth Info in PGN
When on this option will cause the score and depth at which it
- 40 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
was calculated by an engine, and (when available) thinking time
to be saved with the move as a comment to the move, in the format
{score/depth time}. Here 'score'is in pawn units from the point
of view of the player that made the move, with two digits behind
the decimal Pawn.
Save Out-of-Book Info in PGN
When on this option causes the score of the first move the engine
made after coming out of book in an 'Annotator' PGN tag.
Game List
Pops up a dialog where you can select the PGN tags that should appear
on the lines in the `Game List', and their order.
Sound Options
Summons a dialog where you can specify the sounds that should
accompany various events that can occur in XBoard. Most events are
only relevant to ICS play, but the move sound is an important
exception. For each event listed in the dialog, you can select a
standard sound from a menu.
Sound Program
Specifies the command XBoard should invoke to play sounds. The
specified text will be suffixed by the name of the sound file,
and then run as a command.
Sounds Directory
Specifies the directory where XBoard will look for files with the
names of the standard sounds.
User WAV File
When we type a filename here, it can be assigned to the events by
selecting `Above WAV File' from the drop downs.
Try-Out Sound
Play The 'event' triggering the Try-Out sound is pressing of the
`Play' button behind it. This allows you to judge the sounds.
Save Settings Now
Selecting this menu item causes the current XBoard settings to be
written to the settings file, (.xboardrc in your home directory), so
they will also apply in future sessions. Note that some settings are
'volatile', and are not saved, because XBoard considers it too
unlikely that you want those to apply next time. In particular this
applies to the Chess program, and all options giving information on
those Chess programs (such as their directory, if they have their own
opening book, if they are UCI or native XBoard), or the variant you
are playing. Such options would still be understood when they appear
in the settings file in case they were put there with the aid of a
text editor, but they would disappear from the file as soon as you
- 41 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
save the settings.
Note that XBoard no longer pays attention to options values specified
in the .Xresources file. (Specifying key bindings there will still
work, though.) To alter the default of volatile options, you can use
the following method: Rename your ~/.xboardrc settings file (to
~/.yboardrc, say), and create a new file ~/.xboardrc, which only
contains the options
-settingsFile ~/.yboardrc
-saveSettingsFile ~/.yboardrc
This will cause your settings to be saved on ~/.yboardrc in the
future, so that ~/.xboardrc is no longer overwritten. You can then
safely specify volatile options in ~/.xboardrc, either before or after
the settingsFile options. Note that when you specify persistent
options after the settingsFile options in this ~/.xboardrc, you will
essentially turn them into volatile options with the specified value
as default, because that value will overrule the value loaded from the
settings file (being read later).
Save Settings on Exit
Setting this option has no immediate effect, but causes the settings
to be saved when you quit XBoard. What happens then is otherwise
identical to what happens when you use select "Save Settings Now", see
there.
Help Menu
Info XBoard
Displays the XBoard documentation in info format. For this
feature to work, you must have the GNU info program installed on
your system, and the file `xboard.info' must either be present in
the current working directory, or have been installed by the
`make install' command when you built XBoard.
Man XBoard
Displays the XBoard documentation in man page format. The `F1'
key is a keyboard equivalent. For this feature to work, the file
`xboard.6' must have been installed by the `make install' command
when you built XBoard, and the directory it was placed in must be
on the search path for your system's `man' command.
About XBoard
Shows the current XBoard version number.
Other Shortcut Keys
Show Last Move
By hitting `Enter' the last move will be re-animated.
- 42 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
Load Next Game
Loads the next game from the last game record file you loaded.
The `Alt+PgDn' key triggers this action.
Load Previous Game
Loads the previous game from the last game record file you
loaded. The `Alt+PgUp' key triggers this action. Not available
if the last game was loaded from a pipe.
Reload Same Game
Reloads the last game you loaded. Not available if the last game
was loaded from a pipe. Currently no keystroke is assigned to
this ReloadGameProc.
Reload Same Position
Reloads the last position you loaded. Not available if the last
position was loaded from a pipe. Currently no keystroke is
assigned to this ReloadPositionProc.
In the Xaw build of XBoard you can add or remove shortcut keys using
the X resources `paneA.translations'. Here is an example of what
could go into your `.Xdefaults' file:
XBoard*paneA.translations: \
Shift<Key>?: MenuItem(Help.About) \n\
Ctrl<Key>y: MenuItem(Action.Accept) \n\
Ctrl<Key>n: MenuItem(Action.Decline) \n\
Ctrl<Key>i: MenuItem(Nothing)
So the key should always be bound to the action 'MenuItem', with the
(hierarchical) name of the menu item as argument. There are a few
actions available for which no menu item exists: Binding a key to
`Nothing' makes it do nothing, thus removing it as a shortcut key.
Other such functions that can be bound to keys are:
AboutGame, DebugProc (switches the -debug option on or off),
LoadNextGame, LoadPrevGame, ReloadGame, ReloadPosition.
OPTIONS
This section documents the command-line options to XBoard. You can
set these options in two ways: by typing them on the shell command
line you use to start XBoard, or by editing the settings file (usually
~/.xboardrc) to alter the value of the setting that was saved there.
Some of the options cannot be changed while XBoard is running; others
set the initial state of items that can be changed with the Options
menu.
Most of the options have both a long name and a short name. To turn a
boolean option on or off from the command line, either give its long
name followed by the value true or false (`-longOptionName true'), or
- 43 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
give just the short name to turn the option on (`-opt'), or the short
name preceded by `x' to turn the option off (`-xopt'). For options
that take strings or numbers as values, you can use the long or short
option names interchangeably.
Chess Engine Options
-tc or -timeControl minutes[:seconds]
Each player begins with his clock set to the `timeControl'
period. Default: 5 minutes. The additional options
`movesPerSession' and `timeIncrement' are mutually exclusive.
-mps or -movesPerSession moves
When both players have made `movesPerSession' moves, a new
`timeControl' period is added to both clocks. Default: 40 moves.
-inc or -timeIncrement seconds
If this option is specified, `movesPerSession' is ignored.
Instead, after each player's move, `timeIncrement' seconds are
added to his clock. Use `-inc 0' if you want to require the
entire game to be played in one `timeControl' period, with no
increment. Default: -1, which specifies `movesPerSession' mode.
-clock/-xclock or -clockMode true/false
Determines whether or not to display the chess clocks. If
clockMode is false, the clocks are not shown, but the side that
is to play next is still highlighted. Also, unless `searchTime'
is set, the chess engine still keeps track of the clock time and
uses it to determine how fast to make its moves.
-shoMoveTime true/false
When this option is set the time that has been thought about the
current move will be displayed behind the remaining time in
parentheses (in seconds). Default: false.
-st or -searchTime minutes[:seconds]
Tells the chess engine to spend at most the given amount of time
searching for each of its moves. Without this option, the chess
engine chooses its search time based on the number of moves and
amount of time remaining until the next time control. Setting
this option also sets clockMode to false.
-depth or -searchDepth number
Tells the chess engine to look ahead at most the given number of
moves when searching for a move to make. Without this option, the
chess engine chooses its search depth based on the number of
moves and amount of time remaining until the next time control.
With the option, the engine will cut off its search early if it
reaches the specified depth.
- 44 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
-firstNPS number
-secondNPS number
Tells the chess engine to use an internal time standard based on
its node count, rather then wall-clock time, to make its timing
decisions. The time in virtual seconds should be obtained by
dividing the node count through the given number, like the number
was a rate in nodes per second. Xboard will manage the clocks in
accordance with this, relying on the number of nodes reported by
the engine in its thinking output. If the given number equals
zero, it can obviously not be used to convert nodes to seconds,
and the time reported by the engine is used to decrement the
XBoard clock in stead. The engine is supposed to report in CPU
time it uses, rather than wall-clock time, in this mode. This
option can provide fairer conditions for engine-engine matches on
heavily loaded machines, or with very fast games (where the wall
clock is too inaccurate). `showThinking' must be on for this
option to work. Default: -1 (off). Not many engines might
support this yet!
-firstTimeOdds factor
-secondTimeOdds factor
Reduces the time given to the mentioned engine by the given
factor. If pondering is off, the effect is indistinguishable from
what would happen if the engine was running on an n-times slower
machine. Default: 1.
-timeOddsMode mode
This option determines how the case is handled where both engines
have a time-odds handicap. If mode=1, the engine that gets the
most time will always get the nominal time, as specified by the
time-control options, and its opponent's time is renormalized
accordingly. If mode=0, both play with reduced time. Default: 0.
-hideThinkingFromHuman true/false
Controls the Hide Thinking option. See Options Menu. Default:
true. (Replaces the Show-Thinking option of older xboard
versions.)
-thinking/-xthinking or -showThinking true/false
Forces the engine to send thinking output to xboard. Used to be
the only way to control if thinking output was displayed in older
xboard versions, but as the thinking output in xboard 4.3 is also
used for several other purposes (adjudication, storing in PGN
file) the display of it is now controlled by the new option Hide
Thinking. See Options Menu. Default: false. (But if xboard needs
the thinking output for some purpose, it makes the engine send it
despite the setting of this option.)
-ponder/-xponder or -ponderNextMove true/false
Sets the Ponder Next Move menu option. See Options Menu. Default:
true.
- 45 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
-smpCores number
Specifies the maximum number of CPUs an SMP engine is allowed to
use. Only works for engines that support the XBoard/WinBoard-
protocol cores feature.
-mg or -matchGames n
Automatically runs an n-game match between two chess engines,
with alternating colors. If the `loadGameFile' or
`loadPositionFile' option is set, XBoard starts each game with
the given opening moves or the given position; otherwise, the
games start with the standard initial chess position. If the
`saveGameFile' option is set, a move record for the match is
appended to the specified file. If the `savePositionFile' option
is set, the final position reached in each game of the match is
appended to the specified file. When the match is over, XBoard
displays the match score and exits. Default: 0 (do not run a
match).
-mm/-xmm or -matchMode true/false
Setting `matchMode' to true is equivalent to setting `matchGames'
to 1.
-sameColorGames n
Automatically runs an n-game match between two chess engines,
without alternating colors. Otherwise the same applies as for
the `-matchGames' option, over which it takes precedence if both
are specified. (See there.) Default: 0 (do not run a match).
-epd This option puts XBoard in a special mode for solving EPD test-
suites, for the entire duration of the session. In this mode
games are aborted after a single move, and that move will be
compared with the best-move or avoid-move from the EPD position
description from which the 'game' was started. Playing a best
move counts as a win, playing an avoid move as a loss, and
playing any other move counts as a draw. This option should be
used in combination with match mode, and an EPD file of starting
positions with an auto-incrementing index. Color assignment will
be such that the first engine plays all moves, and the second
engine will be never involved. The results for individual
positions, as well as the time used for solving them, will be
reported in the lower pane of the Engine Output window.
-fcp or -firstChessProgram program
-scp or -secondChessProgram program
Name of first and second chess engine, respectively. A second
chess engine is started only in Two Machines (match) mode, or in
Analyze mode with two engines. The second engine is by default
the same as the first. Default for the first engine: `fairymax'.
-fe or -firstEngine nickname
- 46 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
-se or -secondEngine nickname
This is an alternative to the `fcp' and `scp' options for
specifying the first and second engine, for engines that were
already registered (using the `Load Engine' dialog) in XBoard's
settings file. It will not only retrieve the real name of the
engine, but also all options configured with it. (E.g. if it is
UCI, whether it should use book.)
-fb/-xfb or -firstPlaysBlack true/false
In games between two chess engines, firstChessProgram normally
plays white. If this option is true, firstChessProgram plays
black. In a multi-game match, this option affects the colors
only for the first game; they still alternate in subsequent
games.
-fh or -firstHost host
-sh or -secondHost host
Hosts on which the chess engines are to run. The default for each
is `localhost'. If you specify another host, XBoard uses `rsh' to
run the chess engine there. (You can substitute a different
remote shell program for rsh using the `remoteShell' option
described below.)
-fd or -firstDirectory dir
-sd or -secondDirectory dir
Working directories in which the chess engines are to be run.
The default is "", which means to run the chess engine in the
same working directory as XBoard itself. (See the CHESSDIR
environment variable.) This option is effective only when the
chess engine is being run on the local host; it does not work if
the engine is run remotely using the -fh or -sh option.
-initString string or -firstInitString
-secondInitString string
The string that is sent to initialize each chess engine for a new
game. Default:
new
random
Setting this option from the command line is tricky, because you
must type in real newline characters, including one at the very
end. In most shells you can do this by entering a `\' character
followed by a newline. Using the character sequence `\n' in the
string should work too, though.
If you change this option, don't remove the `new' command; it is
required by all chess engines to start a new game.
You can remove the `random' command if you like; including it
causes GNU Chess 4 to randomize its move selection slightly so
- 47 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
that it doesn't play the same moves in every game. Even without
`random', GNU Chess 4 randomizes its choice of moves from its
opening book. Many other chess engines ignore this command
entirely and always (or never) randomize.
You can also try adding other commands to the initString; see the
documentation of the chess engine you are using for details.
-firstComputerString string
-secondComputerString string
The string that is sent to the chess engine if its opponent is
another computer chess engine. The default is `computer\n'.
Probably the only useful alternative is the empty string (`'),
which keeps the engine from knowing that it is playing another
computer.
-reuse/-xreuse or -reuseFirst true/false
-reuse2/-xreuse2 or -reuseSecond true/false
If the option is false, XBoard kills off the chess engine after
every game and starts it again for the next game. If the option
is true (the default), XBoard starts the chess engine only once
and uses it repeatedly to play multiple games. Some old chess
engines may not work properly when reuse is turned on, but
otherwise games will start faster if it is left on.
-firstProtocolVersion version-number
-secondProtocolVersion version-number
This option specifies which version of the chess engine
communication protocol to use. By default, version-number is 2.
In version 1, the "protover" command is not sent to the engine;
since version 1 is a subset of version 2, nothing else changes.
Other values for version-number are not supported.
-firstScoreAbs true/false
-secondScoreAbs true/false
If this option is set, the score reported by the engine is taken
to be that in favor of white, even when the engine plays black.
Important when XBoard uses the score for adjudications, or in PGN
reporting.
-niceEngines priority
This option allows you to lower the priority of the engine
processes, so that the generally insatiable hunger for CPU time
of chess engines does not interfere so much with smooth operation
of XBoard (or the rest of your system). Negative values could
increase the engine priority, which is not recommended.
-firstOptions string
-secondOptions string
The given string is a comma-separated list of (option name=option
value) pairs, like the following example: "style=Karpov,blunder
- 48 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
rate=0". If an option announced by the engine at startup through
the feature commands of the XBoard/WinBoard protocol matches one
of the option names (i.e. "style" or "blunder rate"), it would be
set to the given value (i.e. "Karpov" or 0) through a
corresponding option command to the engine. This provided that
the type of the value (text or numeric) matches as well.
-firstNeedsNoncompliantFEN string
-secondNeedsNoncompliantFEN string
The castling rights and e.p. fields of the FEN sent to the
mentioned engine with the setboard command will be replaced by
the given string. This can for instance be used to run engines
that do not understand Chess960 FENs in variant fischerandom, to
make them at least understand the opening position, through
setting the string to "KQkq -". (Note you also have to give the
e.p. field!) Other possible applications are to provide work-
arounds for engines that want to see castling and e.p. fields in
variants that do not have castling or e.p. (shatranj, courier,
xiangqi, shogi) so that XBoard would normally omit them (string =
"- -"), or to add variant-specific fields that are not yet
supported by XBoard (e.g. to indicate the number of checks in
3check).
-shuffleOpenings
Forces shuffling of the opening setup in variants that normally
have a fixed initial position. Shufflings are symmetric for
black and white, and exempt King and Rooks in variants with
normal castling. Remains in force until a new variant is
selected.
-fischerCastling
Specifies Fischer castling (as in Chess960) should be enabled in
variants that normally would not have it. Remains in force until
a new variant is selected.
UCI + WB Engine Settings
-fUCI or -firstIsUCI true/false
-sUCI or -secondIsUCI true/false
Indicates if the mentioned engine executable file is a UCI
engine, and should be run with the aid of the Polyglot adapter
rather than directly. Xboard will then pass the other UCI options
and engine name to Polyglot on its command line, according to the
option `adapterCommand'.
-fUCCI
-sUCCI
-fUSI
-sUSI
Options similar to `fUCI' and `sUCI', except that they use the
indicated engine with the protocol adapter specified in the
`uxiAdapter' option. This can then be configured for running a
- 49 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
UCCI or USI adapter, as the need arises.
-adapterCommand string
The string contains the command that should be issued by XBoard
to start an engine that is accompanied by the `fUCI' option. Any
identifier following a percent sign in the command (e.g. %fcp)
will be considered the name of an XBoard option, and be replaced
by the value of that option at the time the engine is started.
For starting the second engine, any leading "f" or "first" in the
option name will first be replaced by "s" or "second", before
finding its value. Default: 'polyglot -noini -ec "%fcp" -ed
"%fd"'
-uxiAdapter string
Similar to `adapterCommand', but used for engines accompanied by
the `fUCCI' or `fUSI' option, so you can configure XBoard to be
ready to handle more than one flavor of non-native protocols.
Default: ""
-polyglotDir filename
Gives the name of the directory in which the Polyglot adapter for
UCI engines resides. Default: "".
-usePolyglotBook true/false
Specifies if the Polyglot book should be used as GUI book.
-polyglotBook filename
Gives the filename of the opening book. The book is only used
when the `usePolyglotBook' option is set to true, and the option
`firstHasOwnBookUCI' or `secondHasOwnBookUCI' applying to the
engine is set to false. The engine will be kept in force mode as
long as the current position is in book, and XBoard will select
the book moves for it. Default: "".
-fNoOwnBookUCI or -firstXBook or -firstHasOwnBookUCI true/false
-sNoOwnBookUCI or -secondXBook or -secondHasOwnBookUCI true/false
Indicates if the mentioned engine has its own opening book it
should play from, rather than using the external book through
XBoard. Default: depends on setting of the option
`discourageOwnBooks'.
-discourageOwnBooks true/false
When set, newly loaded engines will be assumed to use the GUI
book, unless they explicitly specify differently. Otherwise they
will be assumed to not use the GUI book, unless the specify
differently (e.g. with `firstXBook'). Default: false.
-bookDepth n
Limits the use of the GUI book to the first n moves of each side.
Default: 12.
- 50 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
-bookVariation n
A value n from 0 to 100 tunes the choice of moves from the GUI
books from totally random to best-only. Default: 50
-mcBookMode
When this volatile option is specified, the probing algorithm of
the GUI book is altered to always select the move that is most
under-represented based on its performance. When all moves are
played in approximately the right proportion, a book miss will be
reported, to give the engine opportunity to explore a new move.
In addition score of the moves will be kept track of during the
session in a book buffer. By playing an match in this mode, a
book will be built from scratch. The only output are the saved
games, which can be converted to an actual book later, with the
`Save Games as Book' command. The latter command can also be
used to pre-fill the book buffer before adding new games based on
the probing algorithm.
-fn string or -firstPgnName string
-sn string or -secondPgnName string
Indicates the name that should be used for the engine in PGN tags
of engine-engine games. Intended to allow you to install
versions of the same engine with different settings, and still
distinguish them. Default: "".
-defaultHashSize n
Sets the size of the hash table to n MegaBytes. Together with the
EGTB cache size this number is also used to calculate the memory
setting of XBoard/WinBoard engines, for those that support the
memory feature of the XBoard/WinBoard protocol. Default: 64.
-defaultCacheSizeEGTB n
Sets the size of the EGTB cache to n MegaBytes. Together with the
hash-table size this number is also used to calculate the memory
setting of XBoard/WinBoard engines, for those that support the
memory feature of the XBoard/WinBoard protocol. Default: 4.
-defaultPathEGTB filename
Gives the name of the directory where the end-game tablebases are
installed, for UCI engines. Default: "/usr/local/share/egtb".
-egtFormats string
Specifies which end-game tables are installed on the computer,
and where. The argument is a comma-separated list of format
specifications, each specification consisting of a format name, a
colon, and a directory path name, e.g.
"nalimov:/usr/local/share/egtb". If the name part matches that of
a format that the engine requests through a feature command,
xboard will relay the path name for this format to the engine
through an egtpath command. One egtpath command for each matching
format will be sent. Popular formats are "nalimov" and "gaviota"
- 51 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
DTM tablebases, syzygy DTZ tablebases and "scorpio" bitbases.
Default: "".
-firstChessProgramNames={names}
This option lets you customize the listbox with chess-engine
names that appears in the `Load Engine' and `Tournament Options'
dialog. It consists of a list of strings, one per line. When an
engine is loaded, the corresponding line is prefixed with "-fcp
", and processed like it appeared on the command line. That
means that apart from the engine command, it can contain any
number of XBoard options you want to use with this engine.
(Commonly used options here are -fd, -firstXBook, -fUCI,
-variant.)
The value of this option is gradually built as you load new
engines through the `Load Engine' menu dialog, with `Add to list'
ticked. To change it in other ways, (e.g. deleting engines), use
the menu item `Edit Engine List' in the `Engine' menu.
Tournament options
-defaultMatchGames n
Sets the number of games that will be used for a match between
two engines started from the menu to n. Also used as games per
pairing in other tournament formats. Default: 10.
-matchPause n
Specifies the duration of the pause between two games of a match
or tournament between engines as n milliseconds. Especially
engines that do not support ping need this option, to prevent
that the move they are thinking on when an opponent unexpectedly
resigns will be counted for the next game, (leading to illegal
moves there). Default: 10000.
-tf filename or -tourneyFile filename
Specifies the name of the tournament file used in match mode to
conduct a multi-player tournament. This file is a special
settings file, which stores the description of the tournament
(including progress info), through normal options (e.g. for time
control, load and save files), and through some special-purpose
options listed below.
-tt number or -tourneyType number
Specifies the type of tourney: 0 = round-robin, N>0 = (multi-
)gauntlet with N gauntlet engines, -1 = Swiss through external
pairing engine. Volatile option, but stored in tourney file.
-cy number or -tourneyCycles number
Specifies the number of cycles in a tourney. Volatile option, but
stored in tourney file.
- 52 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
-participants list
The list is a multi-line text string that specifies engines
occurring in the `firstChesProgramNames' list in the settings
file by their (implied or explicitly given) nicknames, one engine
per line. The mentioned engines will play in the tourney.
Volatile option, but stored in tourney file.
-results string
The string of +=- characters lists the result of all played games
in a tourney. Games currently playing are listed as *, while a
space indicates a game that is not yet played. Volatile option,
but stored in tourney file.
-defaultTourneyName string
Specifies the name of the tournament file XBoard should propose
when the `Match Options' dialog is opened. Any %y, %M, %d, %h,
%m, %s in the string are replaced by the current year, month, day
of the month, hours, minutes, seconds of the current time,
respectively, as two-digit number. A %Y would be replaced by the
year as 4-digit number. Default: empty string.
-pairingEngine filename
Specifies the external program to be used to pair the
participants in Swiss tourneys. XBoard communicates with this
engine in the same way as it communicates with Chess engines. The
only commands sent to the pairing engine are results N
string, (where N is the number of participants, and string the
results so far in the format of the results option), and
pairing N, (where N is the number of the tourney game). To
the latter the pairing engine should answer with A-B, where
A and B are participant numbers (in the range 1-N). (There should
be no reply to the results command.) Default: empty string.
-afterGame string
-afterTourney string
When non-empty, the given string will be executed as a system
command after each tournament game, or after the tourney
completes, respectively. This can be used, for example, to
autmatically run a cross-table generator on the PGN file where
games are saved, to update the tourney standings. Default: ""
-syncAfterRound true/false
-syncAfterCycle true/false
Controls whether different instances of XBoard concurrently
running the same tournament will wait for each other. Defaults:
sync after cycle, but not after round.
-seedBase number
Used to store the seed of the pseudo-random-number generator in
the tourneyFile, so that separate instances of XBoard working on
the same tourney can take coherent 'random' decisions, such as
- 53 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
picking an opening for a given game number.
ICS options
-ics/-xics or -internetChessServerMode true/false
Connect with an Internet Chess Server to play chess against its
other users, observe games they are playing, or review games that
have recently finished. Default: false.
-icshost or -internetChessServerHost host
The Internet host name or address of the chess server to connect
to when in ICS mode. Default: `chessclub.com'. Another popular
chess server to try is `freechess.org'. If your site doesn't
have a working Internet name server, try specifying the host
address in numeric form. You may also need to specify the numeric
address when using the icshelper option with timestamp or
timeseal (see below).
-icsport or -internetChessServerPort port-number
The port number to use when connecting to a chess server in ICS
mode. Default: 5000.
-icshelper or -internetChessServerHelper prog-name
An external helper program used to communicate with the chess
server. You would set it to "timestamp" for ICC (chessclub.com)
or "timeseal" for FICS (freechess.org), after obtaining the
correct version of timestamp or timeseal for your computer. See
"help timestamp" on ICC and "help timeseal" on FICS. This option
is shorthand for `-useTelnet -telnetProgram program'.
-telnet/-xtelnet or -useTelnet true/false
This option is poorly named; it should be called useHelper. If
set to true, it instructs XBoard to run an external program to
communicate with the Internet Chess Server. The program to use is
given by the telnetProgram option. If the option is false (the
default), XBoard opens a TCP socket and uses its own internal
implementation of the telnet protocol to communicate with the
ICS. See Firewalls.
-telnetProgram prog-name
This option is poorly named; it should be called helperProgram.
It gives the name of the telnet program to be used with the
`gateway' and `useTelnet' options. The default is `telnet'. The
telnet program is invoked with the value of
`internetChessServerHost' as its first argument and the value of
`internetChessServerPort' as its second argument. See Firewalls.
-gateway host-name
If this option is set to a host name, XBoard communicates with
the Internet Chess Server by using `rsh' to run the
`telnetProgram' on the given host, instead of using its own
internal implementation of the telnet protocol. You can
- 54 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
substitute a different remote shell program for `rsh' using the
`remoteShell' option described below. See Firewalls.
-internetChessServerCommPort or -icscomm dev-name
If this option is set, XBoard communicates with the ICS through
the given character I/O device instead of opening a TCP
connection. Use this option if your system does not have any
kind of Internet connection itself (not even a SLIP or PPP
connection), but you do have dial-up access (or a hardwired
terminal line) to an Internet service provider from which you can
telnet to the ICS.
The support for this option in XBoard is minimal. You need to set
all communication parameters and tty modes before you enter
XBoard.
Use a script something like this:
stty raw -echo 9600 > /dev/tty00
xboard -ics -icscomm /dev/tty00
Here replace `/dev/tty00' with the name of the device that your
modem is connected to. You might have to add several more options
to these stty commands. See the man pages for `stty' and `tty' if
you run into problems. Also, on many systems stty works on its
standard input instead of standard output, so you have to use `<'
instead of `>'.
If you are using linux, try starting with the script below.
Change it as necessary for your installation.
#!/bin/sh -f
# configure modem and fire up XBoard
# configure modem
(
stty 2400 ; stty raw ; stty hupcl ; stty -clocal
stty ignbrk ; stty ignpar ; stty ixon ; stty ixoff
stty -iexten ; stty -echo
) < /dev/modem
xboard -ics -icscomm /dev/modem
After you start XBoard in this way, type whatever commands are
necessary to dial out to your Internet provider and log in. Then
telnet to ICS, using a command like `telnet chessclub.com 5000'.
Important: See the paragraph below about extra echoes, in
Limitations.
-icslogon or -internetChessServerLogonScript file-name
Whenever XBoard connects to the Internet Chess Server, if it
finds a file with the name given in this option, it feeds the
- 55 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
file's contents to the ICS as commands. The default file name is
`.icsrc'. Usually the first two lines of the file should be your
ICS user name and password. The file can be either in $CHESSDIR,
in XBoard's working directory if CHESSDIR is not set, or in your
home directory.
-msLoginDelay delay
If you experience trouble logging on to an ICS when using the `-
icslogon' option, inserting some delay between characters of the
logon script may help. This option adds `delay' milliseconds of
delay between characters. Good values to try are 100 and 250.
-icsinput/-xicsinput or -internetChessServerInputBox true/false
Sets the ICS Input Box menu option. See Mode Menu. Default:
false.
-autocomm/-xautocomm or -autoComment true/false
Sets the Auto Comment menu option. See Options Menu. Default:
false.
-autoflag/-xautoflag or -autoCallFlag true/false
Sets the Auto Flag menu option. See Options Menu. Default:
false.
-autobs/-xautobs or -autoObserve true/false
Sets the Auto Observe menu option. See Options Menu. Default:
false.
-autoKibitz
Enables kibitzing of the engines last thinking output (depth,
score, time, speed, PV) before it moved to the ICS, in zippy
mode. The option `showThinking' must be switched on for this
option to work. Also diverts similar kibitz information of an
opponent engine that is playing you through the ICS to the
engine-output window, as if the engine was playing locally.
-seekGraph true/false or -sg
Enables displaying of the seek graph by left-clicking the board
when you are logged on to an ICS and currently idle. The seek
graph show all players currently seeking games on the ICS,
plotted according to their rating and the time control of the
game they seek, in three different colors (for rated, unrated and
wild games). Computer ads are displayed as squares, human ads
are dots. Default: false.
-autoRefresh true/false
Enables automatic updating of the seek graph, by having the ICS
send a running update of all newly placed and removed seek ads.
This consumes a substantial amount of communication bandwidth,
and is only supported for FICS and ICC. Default: false.
- 56 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
-backgroundObserve true/false
When true, boards sent to you by the ICS from other games while
you are playing (e.g. because you are observing them) will not be
automatically displayed. Only a summary of time left and
material of both players will appear in the message field above
the board. XBoard will remember the last board it has received
this way, and will display it instead of the position in your own
game when you press the right mouse button. No other information
is stored on such games observed in the background; you cannot
save such a game later, or step through its moves. This feature
is provided solely for the benefit of bughouse players, to enable
them to peek at their partner's game without the need to logon
twice. Default: false.
-dualBoard true/false
In combination with -backgroundObserve true, this option will
display the board of the background game side by side with that
of your own game, so you can have it in view permanently. Any
board or holdings info coming in will be displayed on the
secondary board immediately. This feature is still experimental
and largely unfinished. There is no animation or highlighting of
moves on the secondary board. Default: false.
-disguisePromotedPieces true/false
When set promoted Pawns in crazyhouse/bughouse are displayed
identical to primordial pieces of the same type, rather than
distinguishable. Default: true.
-moves/-xmoves or -getMoveList true/false
Sets the Get Move List menu option. See Options Menu. Default:
true.
-alarm/-xalarm or -icsAlarm true/false
Sets the ICS Alarm menu option. See Options Menu. Default: true.
-icsAlarmTime ms
Sets the time in milliseconds for the ICS Alarm menu option. See
Options Menu. Default: 5000.
lowTimeWarning true/false
Controls a color change of the board as a warning your time is
running out. See Options Menu. Default: false.
-pre/-xpre or -premove true/false
Sets the Premove menu option. See Options Menu. Default: true.
-prewhite/-xprewhite or -premoveWhite
-preblack/-xpreblack or -premoveBlack
-premoveWhiteText string
-premoveBlackText string
Set the menu options for specifying the first move for either
- 57 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
color. See Options Menu. Defaults: false and empty strings, so no
pre-moves.
-quiet/-xquiet or -quietPlay true/false
Sets the Quiet Play menu option. See Options Menu. Default:
false.
-colorizeMessages or -colorize/-xcolorize
Setting colorizeMessages to true tells XBoard to colorize the
messages received from the ICS. Colorization works only if your
xterm supports ISO 6429 escape sequences for changing text
colors. Default: true.
-colorShout foreground,background,bold
-colorSShout foreground,background,bold
-colorCShout foreground,background,bold
-colorChannel1 foreground,background,bold
-colorChannel foreground,background,bold
-colorKibitz foreground,background,bold
-colorTell foreground,background,bold
-colorChallege foreground,background,bold
-colorRequest foreground,background,bold
-colorSeek foreground,background,bold
-colorNormal foreground,background,bold
These options set the colors used when colorizing ICS messages.
All ICS messages are grouped into one of these categories: shout,
sshout, channel 1, other channel, kibitz, tell, challenge,
request (including abort, adjourn, draw, pause, and takeback), or
normal (all other messages).
Each foreground or background argument can be one of the
following: black, red, green, yellow, blue, magenta, cyan, white,
or default. Here ``default'' means the default foreground or
background color of your xterm. Bold can be 1 or 0. If
background is omitted, ``default'' is assumed; if bold is
omitted, 0 is assumed.
-soundProgram progname
If this option is set to a sound-playing program that is
installed and working on your system, XBoard can play sound files
when certain events occur, listed below. The default program
name is "play". If any of the sound options is set to "$", the
event rings the terminal bell by sending a ^G character to
standard output, instead of playing a sound file. If an option
is set to the empty string "", no sound is played for that event.
-soundDirectory directoryname
This option specifies where XBoard will look for sound files,
when these are not given as an absolute path name.
- 58 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
-soundShout filename
-soundSShout filename
-soundCShout filename
-soundChannel filename
-soundChannel1 filename
-soundKibitz filename
-soundTell filename
-soundChallenge filename
-soundRequest filename
-soundSeek filename
These sounds are triggered in the same way as the colorization
events described above. They all default to "", no sound. They
are played only if the colorizeMessages is on. CShout is
synonymous with SShout.
-soundMove filename
This sound is played when a player other than yourself makes a
move. Default: "$".
-soundRoar filename
This sound is played when a Lion makes a hit-and-run or double
capture/ Default: "" (no sound).
-soundIcsAlarm filename
This sound is used by the ICS Alarm menu option. Default: "$".
-soundIcsWin filename
This sound is played when you win an ICS game. Default: "" (no
sound).
-soundIcsLoss filename
This sound is played when you lose an ICS game. Default: "" (no
sound).
-soundIcsDraw filename
This sound is played when you draw an ICS game. Default: "" (no
sound).
-soundIcsUnfinished filename
This sound is played when an ICS game that you are participating
in is aborted, adjourned, or otherwise ends inconclusively.
Default: "" (no sound).
Load and Save options
-lgf or -loadGameFile file
-lgi or -loadGameIndex index
If the `loadGameFile' option is set, XBoard loads the specified
game file at startup. The file name `-' specifies the standard
input. If there is more than one game in the file, XBoard pops up
a menu of the available games, with entries based on their PGN
(Portable Game Notation) tags. If the `loadGameIndex' option is
- 59 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
set to `N', the menu is suppressed and the N th game found in the
file is loaded immediately. The menu is also suppressed if
`matchMode' is enabled or if the game file is a pipe; in these
cases the first game in the file is loaded immediately. Use the
`pxboard' shell script provided with XBoard if you want to pipe
in files containing multiple games and still see the menu. If
the loadGameIndex specifies an index -1, this triggers auto-
increment of the index in `matchMode', which means that after
every game the index is incremented by one, causing each game of
the match to be played from the next game in the file. Similarly,
specifying an index value of -2 causes the index to be
incremented every two games, so that each game in the file is
used twice (with reversed colors). The `rewindIndex' option
causes the index to be reset to the first game of the file when
it has reached a specified value.
-rewindIndex n
Causes a position file or game file to be rewound to its
beginning after n positions or games in auto-increment
`matchMode'. See `loadPositionIndex' and `loadGameIndex'.
default: 0 (no rewind).
-td or -timeDelay seconds
Time delay between moves during `Load Game' or `Analyze File'.
Fractional seconds are allowed; try `-td 0.4'. A time delay value
of -1 tells XBoard not to step through game files automatically.
Default: 1 second.
-sgf or -saveGameFile file
If this option is set, XBoard appends a record of every game
played to the specified file. The file name `-' specifies the
standard output.
-autosave/-xautosave or -autoSaveGames true/false
Sets the Auto Save menu option. See Options Menu. Default:
false. Ignored if `saveGameFile' is set.
-onlyOwnGames true/false
Suppresses auto-saving of ICS observed games. Default: false.
-lpf or -loadPositionFile file
-lpi or -loadPositionIndex index
If the `loadPositionFile' option is set, XBoard loads the
specified position file at startup. The file name `-' specifies
the standard input. If the `loadPositionIndex' option is set to
N, the Nth position found in the file is loaded; otherwise the
first position is loaded. If the loadPositionIndex specifies an
index -1, this triggers auto-increment of the index in
`matchMode', which means that after every game the index is
incremented by one, causing each game of the match to be played
from the next position in the file. Similarly, specifying an
- 60 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
index value of -2 causes the index to be incremented every two
games, so that each position in the file is used twice (with the
engines playing opposite colors). The `rewindIndex' option
causes the index to be reset to the first position of the file
when it has reached a specified value.
-spf or -savePositionFile file
If this option is set, XBoard appends the final position reached
in every game played to the specified file. The file name `-'
specifies the standard output.
-positionDir directory
Specifies the directory where file browsing should start when
using the `Load Position' menu item.
-pgnExtendedInfo true/false
If this option is set, XBoard saves depth, score and time used
for each move that the engine found as a comment in the PGN file.
Default: false.
-pgnTimeLeft true/false
If this option is set, XBoard will save the remaining clock time
for the player that has just moved as part of the
`pgnExtendedInfo', rather than the time that player thought about
his latest move. Default: false.
-pgnEventHeader string
Default: false. Sets the name used in the PGN event tag to
string. Default: "Computer Chess Game".
-pgnNumberTag true/false
Include the (unique) sequence number of a tournament game into
the saved PGN file as a 'number' tag. Default: false.
-saveOutOfBookInfo true/false
Include the information on how the engine(s) game out of its
opening book in a special 'annotator' tag with the PGN file.
Default: true.
-oldsave/-xoldsave or -oldSaveStyle true/false
Sets the Old Save Style menu option. See Options Menu. Default:
false.
-gameListTags string
The character string lists the PGN tags that should be printed in
the Game List, and their order. The meaning of the codes is
e=event, s=site, d=date, o=round, p=players, r=result, w=white
Elo, b=black Elo, t=time control, v=variant, a=out-of-book info,
c=result comment. Default: "eprd"
- 61 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
-ini or -settingsFile filename
-saveSettingsFile filename
@filename
When XBoard encounters an option -settingsFile (or -ini for
short), or @filename, it tries to read the mentioned file, and
substitutes the contents of it (presumaby more command-line
options) in place of the option. In the case of -ini or
-settingsFile, the name of a successfully read settings file is
also remembered as the file to use for saving settings
(automatically on exit, or on user command). An option of the
form @filename does not affect saving. The option
-saveSettingsFile does specify a name of the file to use for
saving, without reading any options from it, and is thus also
effective when the file did not exist yet. So the settings will
be saved to the file specified in the last -saveSettingsFile or
succesfull -settingsFile / -ini command, if any, and in
/etc/xboard/xboard.conf otherwise. Usualy the latter is only
accessible for the system administrator, though, and will be used
to contain system-wide default settings, amongst which a
-saveSettingsFile and -settingsFile options to specify a settings
file accessible to the individual user, such as ~/.xboardrc in
the user's home directory.
-saveSettingsOnExit true/false
Controls saving of options on the settings file. See Options
Menu. Default: true.
User interface options
-noGUI
Suppresses all GUI functions of XBoard (to speed up automated
ultra-fast engine-engine games, which you don't want to watch).
There will be no board or clock updates, no printing of moves,
and no update of the icon on the task bar in this mode.
-logoSize N
This option controls the drawing of player logos next to the
clocks. The integer N specifies the width of the logo in pixels;
the logo height will always be half the width. When N = 0, no
logos will be diplayed. Default: 0.
-firstLogo imagefile
-secondLogo imagefile
Specify the images to be used as player logos when `logoSize' is
non-zero, next to the white and black clocks, respectively.
-autoLogo true/false
-logoDir filename
When `autoLogo' is set, XBoard will search for a PNG image file
with the name of the engine or ICS in the directory specified by
`logoDir'. For a human player it will look for a file
<username>.png in this directory, but only when ~/.logo.png does
- 62 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
not provide one.
-recentEngines number
-recentEngineList list
When the number is larger than zero, it determines how many
recently used engines will be appended at the bottom of the
`Engines' menu. The engines will be saved in your settings file
as the option `recentEngineList', by their nicknames, and the
most recently used one will always be sorted to the top. If the
list after that is longer than the specified number, the last one
is discarded. Changes in the list will only become visible the
next session, provided you saved the settings. Default: 6.
-oneClickMove true/false
When set, this option allows you to enter moves by only clicking
the to- or from-square, when only a single legal move to or from
that square is possible. Double-clicking a piece (or clicking an
already selected piece) will instruct that piece to make the only
capture it can legally do. Default: false.
-monoMouse true/false
When set button 1 clicks on empty squares in Edit Position mode
will be interpreted as button 3 clicks, so they place a piece.
Default: false.
-movesound/-xmovesound or -ringBellAfterMoves true/false
Sets the Move Sound menu option. See Options Menu. Default:
false. For compatibility with old XBoard versions, -bell/-xbell
are also accepted as abbreviations for this option.
-analysisBell N
When N is non-zero, the Move Sound will be played whenever a new
PV arrives in analysis mode after more than N seconds of
analysis. Default: 0.
-exit/-xexit or -popupExitMessage true/false
Sets the Popup Exit Message menu option. See Options Menu.
Default: true.
-popup/-xpopup or -popupMoveErrors true/false
Sets the Popup Move Errors menu option. See Options Menu.
Default: false.
-queen/-xqueen or -alwaysPromoteToQueen true/false
Sets the Always Queen menu option. See Options Menu. Default:
false.
-sweepPromotions true/false
Sets the `Almost Always Promote to Queen' menu option. See
Options Menu. Default: false.
- 63 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
-legal/-xlegal or -testLegality true/false
Sets the Test Legality menu option. See Options Menu. Default:
true.
-size or -boardSize (sizeName | n1,n2,n3,n4,n5,n6,n7)
Determines how large the board will be, by selecting the pixel
size of the pieces and setting a few related parameters. The
sizeName can be one of: Titanic, giving 129x129 pixel pieces,
Colossal 116x116, Giant 108x108, Huge 95x95, Big 87x87, Large
80x80, Bulky 72x72, Medium 64x64, Moderate 58x58, Average 54x54,
Middling 49x49, Mediocre 45x45, Small 40x40, Slim 37x37, Petite
33x33, Dinky 29x29, Teeny 25x25, or Tiny 21x21. Xboard installs
with a set of scalable (svg) piece images, which it scales to any
of the requested sizes. The square size can further be
continuously scaled by sizing the board window, but this only
adapts the size of the pieces, and has no effect on the width of
the grid lines or the font choice (both of which would depend on
he selected boardSize). The default depends on the size of your
screen; it is approximately the largest size that will fit
without clipping.
You can select other sizes or vary other layout parameters by
providing a list of comma-separated values (with no spaces) as
the argument. You do not need to provide all the values; for any
you omit from the end of the list, defaults are taken from the
nearest built-in size. The value `n1' gives the piece size, `n2'
the width of the black border between squares, `n3' the desired
size for the clockFont, `n4' the desired size for the coordFont,
`n5' the desired size for the messageFont, `n6' the smallLayout
flag (0 or 1), and `n7' the tinyLayout flag (0 or 1). All
dimensions are in pixels. If the border between squares is
eliminated (0 width), the various highlight options will not
work, as there is nowhere to draw the highlight. If smallLayout
is 1 and `titleInWindow' is true, the window layout is rearranged
to make more room for the title. If tinyLayout is 1, the labels
on the menu bar are abbreviated to one character each and the
buttons in the button bar are made narrower.
-overrideLineGap n
When n >= 0, this forces the width of the black border between
squares to n pixels for any board size. Mostly used to suppress
the grid entirely by setting n = 0, e.g. in xiangqi or just
getting a prettier picture. When n < 0 this the size-dependent
width of the grid lines is used. Default: -1.
-coords/-xcoords or -showCoords true/false
Sets the Show Coords menu option. See Options Menu. Default:
false. The `coordFont' option specifies what font to use.
-autoraise/-xautoraise or -autoRaiseBoard true/false
Sets the Auto Raise Board menu option. See Options Menu.
- 64 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
Default: true.
-autoflip/-xautoflip or -autoFlipView true/false
Sets the Auto Flip View menu option. See Options Menu. Default:
true.
-flip/-xflip or -flipView true/false
If Auto Flip View is not set, or if you are observing but not
participating in a game, then the positioning of the board at the
start of each game depends on the flipView option. If flipView
is false (the default), the board is positioned so that the white
pawns move from the bottom to the top; if true, the black pawns
move from the bottom to the top. In any case, the Flip menu
option (see Options Menu) can be used to flip the board after the
game starts.
-title/-xtitle or -titleInWindow true/false
If this option is true, XBoard displays player names (for ICS
games) and game file names (for `Load Game') inside its main
window. If the option is false (the default), this information is
displayed only in the window banner. You probably won't want to
set this option unless the information is not showing up in the
banner, as happens with a few X window managers.
-buttons/-xbuttons or -showButtonBar True/False
If this option is False, xboard omits the [<<] [<] [P] [>] [>>]
button bar from the window, allowing the message line to be
wider. You can still get the functions of these buttons using
the menus or their keyboard shortcuts. Default: true.
-evalZoom factor
The score interval (-1,1) is blown up on the vertical axis of the
Evaluation Graph by the given factor. Default: 1
-evalThreshold n
Score below n (centiPawn) are plotted as 0 in the Evaluation
Graph. Default: 25
-mono/-xmono or -monoMode true/false
Determines whether XBoard displays its pieces and squares with
two colors (true) or four (false). You shouldn't have to specify
`monoMode'; XBoard will determine if it is necessary.
-showTargetSquares true/false
Determines whether XBoard can highlight the squares a piece has
legal moves to, when you grab that piece with the mouse.
Default: false.
-flashCount count
-flashRate rate
- 65 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
-flash/-xflash
These options enable flashing of pieces when they land on their
destination square. `flashCount' tells XBoard how many times to
flash a piece after it lands on its destination square.
`flashRate' controls the rate of flashing (flashes/sec).
Abbreviations: `flash' sets flashCount to 3. `xflash' sets
flashCount to 0. Defaults: flashCount=0 (no flashing),
flashRate=5.
-highlight/-xhighlight or -highlightLastMove true/false
Sets the Highlight Last Move menu option. See Options Menu.
Default: false.
-highlightMoveWithArrow true/false
Sets the Highlight with Arrow menu option. See Options Menu.
Default: false.
-blind/-xblind or -blindfold true/false
Sets the Blindfold menu option. See Options Menu. Default:
false.
-periodic/-xperiodic or -periodicUpdates true/false
Controls updating of current move andnode counts in analysis
mode. Default: true.
-fSAN
-sSAN
Causes the PV in thinking output of the mentioned engine to be
converted to SAN before it is further processed. Warning: this
might lose engine output not understood by the parser, and uses a
lot of CPU power. Default: the PV is displayed exactly as the
engine produced it.
-showEvalInMoveHistory true/false
Controls whether the evaluation scores and search depth of engine
moves are displayed with the move in the move-history window.
Default: true.
-clockFont font
The font used for the clocks. If the option value is a pattern
that does not specify the font size, XBoard tries to choose an
appropriate font for the board size being used. Default Xaw:
-*-helvetica-bold-r-normal--*-*-*-*-*-*-*-*. Default GTK: Sans
Bold %d.
-coordFont font
The font used for rank and file coordinate labels if `showCoords'
is true. If the option value is a pattern that does not specify
the font size, XBoard tries to choose an appropriate font for the
board size being used. Default Xaw: -*-helvetica-bold-r-normal-
-*-*-*-*-*-*-*-*. Default GTK: Sans Bold %d.
- 66 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
-messageFont font
The font used for popup dialogs, menus, etc. If the option value
is a pattern that does not specify the font size, XBoard tries to
choose an appropriate font for the board size being used.
Default Xaw: -*-helvetica-medium-r-normal--*-*-*-*-*-*-*-*.
Default GTK: Sans Bold %d
-tagsFont font
The font used in the Edit Tags dialog. If the option value
contains %d, XBoard will replace it by an appropriate font for
the board size being used. (Only used in GTK build.) Default:
Sans Normal %d.
-commentFont font
The font used in the Edit Comment dialog. If the option value
contains %d, XBoard will replace it by an appropriate font for
the board size being used. (Only used in GTK build.) Default:
Sans Normal %d.
-icsFont font
The font used to display ICS output in the ICS Chat window. As
ICS output often contains tables aligned by spaces, a mono-space
font is recommended here. If the option value contains %d,
XBoard will replace it by an appropriate font for the board size
being used. (Only used in GTK build.) Default: Monospace Normal
%d.
-moveHistoryFont font
The font used in Move History and Engine Output windows. As
these windows display mainly moves, one could use a figurine font
here. If the option value contains %d, XBoard will replace it by
an appropriate font for the board size being used. (Only used in
GTK build.) Default: Sans Normal %d.
-gameListFont font
The font used in the listbox of the Game List window. If the
option value contains %d, XBoard will replace it by an
appropriate font for the board size being used. (Only used in
GTK build.) Default: Sans Bold %d.
-fontSizeTolerance tol
In the font selection algorithm, a nonscalable font will be
preferred over a scalable font if the nonscalable font's size
differs by `tol' pixels or less from the desired size. A value
of -1 will force a scalable font to always be used if available;
a value of 0 will use a nonscalable font only if it is exactly
the right size; a large value (say 1000) will force a nonscalable
font to always be used if available. Default: 4.
-pid or -pieceImageDirectory dir
This options control what piece images xboard uses. XBoard will
- 67 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
look in the specified directory for an image in png or svg format
for every piece type, with names like BlackQueen.svg,
WhiteKnight.svg etc. When neither of these is found (or no valid
directory is specified) XBoard will first ty to use an image
White/BlackTile.svg in that same directory, and if that is not
present either use the svg piece that was installed with it (from
the source-tree directory `svg'). Both svg and png images will
be scaled by XBoard to the required size, but the png pieces lose
much in quality when scaled too much. Default: "".
-inscriptions utf8string
The positions in the utf8string correspond to XBoard's piece
types, and for each type a glyph can be defined. This glyph will
then be rendered on top of the image for the piece. This is
useful in combination with the White/BlackTile.svg images, which
could be the image of a blank Shogi tile, for writing the kanji
piece name on top of it on the fly. Default: "".
-whitePieceColor color
-blackPieceColor color
-lightSquareColor color
-darkSquareColor color
-highlightSquareColor color
-preoveHighlightColor color
-lowTimeWarningColor color
Colors to use for the pieces, squares, and square highlights.
Defaults:
-whitePieceColor #FFFFCC
-blackPieceColor #202020
-lightSquareColor #C8C365
-darkSquareColor #77A26D
-highlightSquareColor #FFFF00
-premoveHighlightColor #FF0000
-lowTimeWarningColor #FF0000
On a grayscale monitor you might prefer:
-whitePieceColor gray100
-blackPieceColor gray0
-lightSquareColor gray80
-darkSquareColor gray60
-highlightSquareColor gray100
-premoveHighlightColor gray70
-lowTimeWarningColor gray70
The PieceColor options only work properly if the image files
defining the pieces were pure black & white (possibly anti-
aliased to produce gray scales and semi-transparancy), like the
pieces images that come with the install. Their effect on
- 68 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
colored pieces is undefined. The SquareColor option only have an
effect when no board textures are used.
-trueColors true/false
When set, this option suppresses the effect of the PieceColor
options mentioned above. This is recommended for images that are
already colored.
-useBoardTexture true/false
-liteBackTextureFile filename
-darkBackTextureFile filename
Indicate the png image files to be used for drawing the board
squares, and if they should be used rather than using simple
colors. The algorithm for cutting squares out of a given bitmap
is such that the picture is perfectly reproduced when a bitmap
the size of the complete board is given. If the filename ends in
"-NxM.png", with integer N and M, it is assumed to contain a
bitmap of a complete board of N files and M ranks, and XBoard
will scale it to exactly match the current square size. If N=M=0
it scales the entire bitmap to the size of the board,
irrespective of the number of files and ranks of the latter.
Without any -NxM suffix textures are only blown up by an integer
factor when they are smaller than the square size, or, when the
name starts with "xq", too small to cover the complete Xiangqi
board. Default: false and ""
-drag/-xdrag or -animateDragging true/false
Sets the Animate Dragging menu option. See Options Menu.
Default: true.
-animate/-xanimate or -animateMoving true/false
Sets the Animate Moving menu option. See Options Menu. Default:
true.
-animateSpeed n
Number of milliseconds delay between each animation frame when
Animate Moves is on.
-autoDisplayComment true/false
-autoDisplayTags true/false
If set to true, these options cause the window with the move
comments, and the window with PGN tags, respectively, to pop up
automatically when such tags or comments are encountered during
the replaying a stored or loaded game. Default: true.
-pasteSelection true/false
If this option is set to true, the Paste Position and Paste Game
options paste from the currently selected text. If false, they
paste from the clipboard. Default: false.
- 69 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
-autoCopyPV true|false
When this option is set, the position displayed on the board when
you terminate a PV walk (initiated by a right-click on board or
engine-output window) will be automatically put on the clipboard
as FEN. Default: false.
-dropMenu true|false
This option allows you to emulate old behavior, where the right
mouse button brings up the (now deprecated) drop menu rather than
displaying the position at the end of the principal variation.
Default: False.
-pieceMenu true|false
This option allows you to emulate old behavior, where the right
mouse button brings up the (now deprecated) piece menu in Edit
Position mode. From this menu you can select the piece to put on
the square you clicked to bring up the menu, or select items such
as `clear board'. You can also `promote' or `demote' a clicked
piece to convert it into an unorthodox piece that is not directly
in the menu, or give the move to `black' or `white'.
-variations true|false
When this option is on, you can start new variations in Edit Game
or Analyze mode by holding the Shift key down while entering a
move. When it is off, the Shift key will be ignored. Default:
False.
-appendPV true|false
When this option is on, a button 3 click left of a PV in the
Engine Output window will play the first move of that PV in
Analyze mode, or as many moves as you walk through it by moving
the mouse. Default: False.
-absoluteAnalysisScores true|false
When true, scores on the Engine Output window during analysis
will be printed from the white point-of-view, rather than the
side-to-move point-of-view. Default: False.
-scoreWhite true|false
When true, scores will always be printed from the white point-
of-view, rather than the side-to-move point-of-view. Default:
False.
-memoHeaders true|false
When true, column headers will be displayed in the Engine Output
window for the depth, score, time and nodes data. A button 3
click on these headers will hide or show the corresponding data.
(Not intended for dynamic use, as already printed data of the
current search will not be affected!) Defaul: False.
- 70 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
Adjudication Options
-adjudicateLossThreshold n
If the given value is non-zero, XBoard adjudicates the game as a
loss if both engines agree for a duration of 6 consecutive ply
that the score is below the given score threshold for that
engine. Make sure the score is interpreted properly by XBoard,
using `-firstScoreAbs' and `-secondScoreAbs' if needed. Default:
0 (no adjudication)
-adjudicateDrawMoves n
If the given value is non-zero, XBoard adjudicates the game as a
draw if after the given number of moves it was not yet decided.
Default: 0 (no adjudication)
-checkMates true/false
If this option is set, XBoard detects all checkmates and
stalemates, and ends the game as soon as they occur. Legality-
testing must be switched on for this option to work. Default:
true
-testClaims true/false
If this option is set, XBoard verifies all result claims made by
engines, and those who send false claims will forfeit the game
because of it. Legality-testing must be switched on for this
option to work. Default: true
-materialDraws true/false
If this option is set, XBoard adjudicates games as draws when
there is no sufficient material left to inflict a checkmate. This
applies to KBKB with like bishops (any number, actually), and to
KBK, KNK and KK. Legality-testing must be switched on for this
option to work. Default: true
-trivialDraws true/false
If this option is set, XBoard adjudicates games as draws that
cannot be usually won without opponent cooperation. This applies
to KBKB with unlike bishops, and to KBKN, KNKN, KNNK, KRKR and
KQKQ. The draw is called after 6 ply into these end-games, to
allow quick mates that can occur in some exceptional positions to
be found by the engines. KQKQ does not really belong in this
category, and might be taken out in the future. (When bitbase-
based adjudications are implemented.) Legality-testing must be on
for this option to work. Default: false
-ruleMoves n
If the given value is non-zero, XBoard adjudicates the game as a
draw after the given number of consecutive reversible moves.
Engine draw claims are always accepted after 50 moves,
irrespective of the given value of n.
- 71 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
-repeatsToDraw n
If the given value is non-zero, xboard adjudicates the game as a
draw if a position is repeated the given number of times. Engines
draw claims are always accepted after 3 repeats, (on the 3rd
occurrence, actually), irrespective of the value of n. Beware
that positions that have different castling or en-passant rights
do not count as repeats, XBoard is fully e.p. and castling aware!
Install options
--show-config parameter
When called with this option, XBoard will close immediately after
printing the value of the indicated configuration parameter, or,
when no parameter was given, after printing a list of all such
parameters. Currently the only valid values for parameter are
Datadir and Sysconfdir. This option can be used by install
scripts for board themes to figure out where the currently active
XBoard stores its data.
-date timestamp
-saveDate timestamp
These options specify an epoch as an integer number. The
`saveDate' option is written by XBoard in the settings file every
time the settings are saved, with the current time, so that later
runs of XBoard can know this. The `date' option can be included
in settings files to indicate when lines following it were added
to those files. Some options will be ignored if the epoch
specified by the latest `date' option predates the -saveDate
setting (implying they must have been seen before).
-autoInstall list
When the list is set to a non-empty string, XBoard will scan the
operating system's plugin directory for engines supporting UCI
and XBoard protocol at startup. When it finds an engine that was
installed after it last saved its settings, a line to launch that
engine (as per specs in the plugin file) is appended to the
-firstChessProgramNames list of installed engines. In the future
it will be possible to use the autoInstall list to limit this
automatic adding of engines based on the chess variant they play.
-addMasterOption string
Adds the mentioned string as an additional line of XBoard's
master settings file, after adding a line with a `date' option to
timestamp it. Intended to add options of the 'install' type (see
below) to the master file, which will then be processed by any
XBoard that has not seen them since it last saved its settings.
-autoClose
The presence of this option cause XBoard to close immediately
after processing all its options (from settings file and command
line). Typically used from install scripts together with options
that change XBoard's settings files, so that XBoard can be run in
- 72 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
batch mode rather than interactively.
-installEngine string
Adds the given string as an additional line to the value of the
`firstChessProgramNames' option when the -saveDate setting
preceeds the -date setting. Intended for adding to the master
settings file with the aid of -addMasterOption in the install
script of engines, as a method for broadcasting the presence of a
new engine to all users, which would then see it automatically
registered with XBoard. Made obsolete by the advent of the
plugin standard (see the `autoInstall' option), which broadcasts
such presence in a non-XBoard-specific way by dropping *.eng
files in a certain system directory.
-installTheme string
Adds the given string as an additional line to the value of the
-themeNames option when the -saveDate setting preceeds the -date
setting. Intended for adding to the master settings file with
the aid of -addMasterOption in the install script of board
graphics themes, as a method for broadcasting the availability of
a new theme to all users, who would then see the theme appear
automatically in the listbox in the View Board menu dialog next
time they run XBoard.
Other options
-ncp/-xncp or -noChessProgram true/false
If this option is true, XBoard acts as a passive chessboard; it
does not start a chess engine at all. Turning on this option also
turns off clockMode. Default: false.
-viewer
-viewerOptions string
Presence of the volatile option `viewer' on the command line will
cause the value of the persistent option `viewerOptions' as
stored in the settings file to be appended to the command line.
The `view' option will be used by desktop associations with game
or position file types, so that `viewerOptions' can be used to
configure the exact mode XBoard will start in when it should act
on such a file (e.g. in -ncp mode, or analyzing with your
favorite engine). The options are also automatically appended
when Board is invoked with a single argument not being an option
name, which is then assumed to be the name of a `loadGameFile' or
(when the name ends in .fen) a `loadPositionFile'. Default: "-
ncp -engineOutputUp false -saveSettingsOnExit false".
-tourneyOptions string
When XBoard is invoked with a single argument that is a file with
.trn extension, it will assume this argument to be the value of a
`tourneyFile' option, and append the value of the persistent
option `tourneyOptions' as stored in the settings file to the
command line. Thus the value of `tourneyOptions' can be used to
- 73 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
configure XBoard to automatically start running a tournament when
it should act on such a file. Default: "-ncp -mm
-saveSettingsOnExit false".
-mode or -initialMode modename
If this option is given, XBoard selects the given modename from
the Mode menu after starting and (if applicable) processing the
loadGameFile or loadPositionFile option. Default: "" (no
selection). Other supported values are MachineWhite,
MachineBlack, TwoMachines, Analysis, AnalyzeFile, EditGame,
EditPosition, and Training.
-variant varname
Activates (sometimes partial) support for playing chess variants
against a local engine or editing variant games. This flag is
not needed in ICS mode. Recognized variant names are:
normal Normal chess
wildcastle Shuffle chess, king can castle from d file
nocastle Shuffle chess, no castling allowed
fischerandom Fischer Random shuffle chess
bughouse Bughouse, ICC/FICS rules
crazyhouse Crazyhouse, ICC/FICS rules
losers Lose all pieces or get mated (ICC wild 17)
suicide Lose all pieces including king (FICS)
giveaway Try to have no legal moves (ICC wild 26)
twokings Weird ICC wild 9
kriegspiel Opponent's pieces are invisible
atomic Capturing piece explodes (ICC wild 27)
3check Win by giving check 3 times (ICC wild 25)
shatranj An ancient precursor of chess (ICC wild 28)
xiangqi Chinese Chess (on a 9x10 board)
shogi Japanese Chess (on a 9x9 board & piece drops)
capablanca Capablanca Chess (10x8 board, with Archbishop
and Chancellor pieces)
gothic similar, with a better initial position
caparandom An FRC-like version of Capablanca Chess (10x8)
janus A game with two Archbishops (10x8 board)
courier Medieval intermediate between shatranj and
modern Chess (on 12x8 board)
falcon Patented 10x8 variant with two Falcon pieces
berolina Pawns capture straight ahead, and move diagonally
cylinder Pieces wrap around the board edge
knightmate King moves as Knight, and vice versa
super Superchess (shuffle variant with 4 exo-pieces)
makruk Thai Chess (shatranj-like, P promotes on 6th rank)
asean ASEAN Chess (a modernized version of Makruk)
spartan Spartan Chess (black has unorthodox pieces)
great Great Shatranj, a 10x8 variant without sliders
grand Grand Chess, on 10x10 with Capablanca pieces
lion Mighty-Lion Chess, with a multi-capturing Lion
- 74 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
elven Eleven Chess, with Lion and crowned sliders on 10x10
chu Chu Shogi, historic 12x12 variant with 2x46 pieces
fairy A catchall variant in which all piece types
known to XBoard can participate (8x8)
unknown Catchall for other unknown variants
In the shuffle variants, XBoard does shuffle the pieces, although
you can still do it by hand using Edit Position. Some variants
are supported only in ICS mode, including bughouse, and
kriegspiel. Berolina and cylinder chess are only partially
supported, and can only be played with legality testing off.
Apart from these standard variants, engines can define variants
of arbitrary names, briefing XBoard transparently on the rules
for piece movement, board size and initial setup, so that they
work nearly as well as fully-supported standard variants. (But
obviously only while using that engine.) The user might have to
alter the adjudication settings for some variants, however. E.g.
it makes no sense to adjudicate a draw after 50 reversible moves
in variants that have a 64-move rule, or no similar rule at all.
Default: "normal". Except when the first engine gave an explicit
list of variants it supports, and 'normal' is not amongst those.
In that case the first variant the engine mentioned it did play
will be chosen.
-boardHeight N
Allows you to set a non-standard number of board ranks in any
variant. If the height is given as -1, the default height for the
variant is used. Default: -1
-boardWidth N
Allows you to set a non-standard number of board files in any
variant. If the width is given as -1, the default width for the
variant is used. With a non-standard width, the initial position
will always be an empty board, as the usual opening array will
not fit. Default: -1
-holdingsSize N
Allows you to set a non-standard size for the holdings in any
variant. If the size is given as -1, the default holdings size
for the variant is used. The first N piece types will go into the
holdings on capture, and you will be able to drop them on the
board in stead of making a normal move. If size equals 0, there
will be no holdings. Default: -1
-defaultFrcPosition N
Specifies the number of the opening position in shuffle games
like Chess960. A value of -1 means the position is randomly
generated by XBoard at the beginning of every game. Default: -1
- 75 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
-pieceToCharTable string
The characters that are used to represent the piece types XBoard
knows in FEN diagrams and SAN moves. You should not have to use
this option often: each variant has its own default setting for
the piece representation in FEN, which should be sufficient in
normal use. The string argument has to specify an even number of
pieces (or it will be ignored), as white and black pieces have to
be given separately (in that order). The last letter for each
color will be the King. The letters before that will be PNBRQ and
then a whole host of fairy pieces in an order that has not fully
crystallized yet (currently FEACWMOHIJGDVLSU, F=Ferz, Elephant,
A=Archbishop, C=Chancellor, W=Wazir, M=Commoner, O=Cannon,
H=Nightrider). You should list at least all pieces that occur in
the variant you are playing. If you have fewer characters in the
string than XBoard has pieces, the pieces not mentioned will get
assigned a period, and will not be usable in the variant. You
can also explicitly assign pieces a period, in which case they
will not be counted in deciding which captured pieces can go into
the holdings. A tilde '~' as a piece name does mean this piece
is used to represent a promoted Pawn in crazyhouse-like games,
i.e. on capture it turns back to a Pawn. A '+' similarly
indicates the piece is a shogi-style promoted piece, that should
revert to its non-promoted version on capture (rather than to a
Pawn). By default the second 11 pieces known to XBoard are the
promoted forms of the first 11. A piece specified by the
character combination ^ plus letter will be assumed to be the
promoted form of the piece indicated by that letter, and get a
'+' assigned. To get around the limitation of the alphabet,
piece IDs can also be 'dressed letters', i.e. a single letter
(upper case for white, lower case for black) followed by a single
quote or an exclamation point. Default: "" (meaning the default
for the variant is used).
-pieceNickNames string
The characters in the string are interpreted the same way as in
the `pieceToCharTable' option. But on input, piece-ID letters are
first looked up in the nicknames, and only if not defined there,
in the normal pieceToCharTable. This allows you to have two
letters designate the same piece, (e.g. N as an alternative to H
for Horse in Xiangqi), to make reading of non-compliant notations
easier. Default: ""
-colorNickNames string
The side-to-move field in a FEN will be first matched against the
letters in the string (first character for white, second for
black), before it is matched to the regular 'w' and 'b'. This
makes it easier to read non-compliant FENs, which, say, use 'r'
for white. Default: ""
-debug/-xdebug or -debugMode true/false
Turns on debugging printout.
- 76 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
-debugFile filename or -nameOfDebugFile filename
Sets the name of the file to which XBoard saves debug information
(including all communication to and from the engines). A `%d' in
the given file name (e.g. game%d.debug) will be replaced by the
unique sequence number of a tournament game, so that the debug
output of each game will be written on a separate file.
-engineDebugOutput number
Specifies how XBoard should handle unsolicited output from the
engine, with respect to saving it in the debug file. The output
is further (hopefully) ignored. If number=0, XBoard refrains from
writing such spurious output to the debug file. If number=1, all
engine output is written faithfully to the debug file. If
number=2, any protocol-violating line is prefixed with a '#'
character, as the engine itself should have done if it wanted to
submit info for inclusion in the debug file. This option is
provided for the benefit of applications that use the debug file
as a source of information, such as the broadcaster of live games
TLCV / TLCS. Such applications can be protected from spurious
engine output that might otherwise confuse them.
-rsh or -remoteShell shell-name
Name of the command used to run programs remotely. The default is
`rsh' or `remsh', determined when XBoard is configured and
compiled.
-ruser or -remoteUser user-name
User name on the remote system when running programs with the
`remoteShell'. The default is your local user name.
-userName username
Name under which the Human player will be listed in the PGN file.
Default is the login name on your local computer.
-delayBeforeQuit number
-delayAfterQuit number
These options order pauses before and after sending the "quit"
command to an engine that must be terminated. The pause between
quit and the previous command is specified in milliseconds. The
pause after quit is used to schedule a kill signal to be sent to
the engine process after the number of specified seconds plus
one. This signal is a different one as the terminiation signal
described in the protocol specs which engines can suppress or
ignore, and which is sent directly after the "quit" command.
Setting `delayAfterQuit' to -1 will suppress sending of the kill
signal. Default: 0
-searchMode n
The integer n encodes the mode for the `find position' function.
Default: 1 (= Exact position match)
- 77 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
-eloThresholdBoth elo
-eloThresholdAny elo
Defines a lower limit for the Elo rating, which has to be
surpassed before a game will be considered when searching for a
board position. Default: 0
-dateThreshold year
Only games not played before the given year will be considered
when searching for a board position
CHESS SERVERS
An "Internet Chess Server", or "ICS", is a place on the Internet where
people can get together to play chess, watch other people's games, or
just chat. You can use either `telnet' or a client program like
XBoard to connect to the server. There are thousands of registered
users on the different ICS hosts, and it is not unusual to meet 200 on
both chessclub.com and freechess.org.
Most people can just type `xboard -ics' to start XBoard as an ICS
client. Invoking XBoard in this way connects you to the Internet
Chess Club (ICC), a commercial ICS. You can log in there as a guest
even if you do not have a paid account. To connect to the largest
Free ICS (FICS), use the command `xboard -ics -icshost freechess.org'
instead, or substitute a different host name to connect to your
favorite ICS. For a full description of command-line options that
control the connection to ICS and change the default values of ICS
options, see ICS options.
While you are running XBoard as an ICS client, you use the terminal
window that you started XBoard from as a place to type in commands and
read information that is not available on the chessboard.
The first time you need to use the terminal is to enter your login
name and password, if you are a registered player. (You don't need to
do this manually; the `icsLogon' option can do it for you. See ICS
options.) If you are not registered, enter `g' as your name, and the
server will pick a unique guest name for you.
Some useful ICS commands include
help <topic>
to get help on the given <topic>. To get a list of possible
topics type "help" without topic. Try the help command before
you ask other people on the server for help.
For example `help register' tells you how to become a registered
ICS player.
who <flags>
to see a list of people who are logged on. Administrators
- 78 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
(people you should talk to if you have a problem) are marked with
the character `*', an asterisk. The <flags> allow you to display
only selected players: For example, `who of' shows a list of
players who are interested in playing but do not have an
opponent.
games
to see what games are being played
match <player> [<mins>] [<inc>]
to challenge another player to a game. Both opponents get <mins>
minutes for the game, and <inc> seconds will be added after each
move. If another player challenges you, the server asks if you
want to accept the challenge; use the `accept' or `decline'
commands to answer.
accept
decline
to accept or decline another player's offer. The offer may be to
start a new game, or to agree to a `draw', `adjourn' or `abort'
the current game. See Action Menu.
If you have more than one pending offer (for example, if more
than one player is challenging you, or if your opponent offers
both a draw and to adjourn the game), you have to supply
additional information, by typing something like `accept
<player>', `accept draw', or `draw'.
draw
adjourn
abort
asks your opponent to terminate a game by mutual agreement.
Adjourned games can be continued later. Your opponent can either
`decline' your offer or accept it (by typing the same command or
typing `accept'). In some cases these commands work immediately,
without asking your opponent to agree. For example, you can
abort the game unilaterally if your opponent is out of time, and
you can claim a draw by repetition or the 50-move rule if
available simply by typing `draw'.
finger <player>
to get information about the given <player>. (Default: yourself.)
vars to get a list of personal settings
set <var> <value>
to modify these settings
observe <player>
to observe an ongoing game of the given <player>.
- 79 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
examine
oldmoves
to review a recently completed game
Some special XBoard features are activated when you are in examine
mode on ICS. See the descriptions of the menu commands `Forward',
`Backward', `Pause', `ICS Client', and `Stop Examining' on the Edit
Menu, Mode Menu, and Action Menu.
FIREWALLS
By default, XBoard communicates with an Internet Chess Server by
opening a TCP socket directly from the machine it is running on to the
ICS. If there is a firewall between your machine and the ICS, this
won't work. Here are some recipes for getting around common kinds of
firewalls using special options to XBoard. Important: See the
paragraph in the below about extra echoes, in Limitations.
Suppose that you can't telnet directly to ICS, but you can telnet to a
firewall host, log in, and then telnet from there to ICS. Let's say
the firewall is called `firewall.example.com'. Set command-line
options as follows:
xboard -ics -icshost firewall.example.com -icsport 23
Then when you run XBoard in ICS mode, you will be prompted to log in
to the firewall host. This works because port 23 is the standard
telnet login service. Do so, then telnet to ICS, using a command like
`telnet chessclub.com 5000', or whatever command the firewall provides
for telnetting to port 5000.
If your firewall lets you telnet (or rlogin) to remote hosts but
doesn't let you telnet to port 5000, you may be able to connect to the
chess server on port 23 instead, which is the port the telnet program
uses by default. Some chess servers support this (including
chessclub.com and freechess.org), while some do not.
If your chess server does not allow connections on port 23 and your
firewall does not allow you to connect to other ports, you may be able
to connect by hopping through another host outside the firewall that
you have an account on. For instance, suppose you have a shell
account at `foo.edu'. Follow the recipe above, but instead of typing
`telnet chessclub.com 5000' to the firewall, type `telnet foo.edu' (or
`rlogin foo.edu'), log in there, and then type `telnet chessclub.com
5000'.
Suppose that you can't telnet directly to ICS, but you can use rsh to
run programs on a firewall host, and that host can telnet to ICS.
Let's say the firewall is called `rsh.example.com'. Set command-line
options as follows:
- 80 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
xboard -ics -gateway rsh.example.com -icshost chessclub.com
Then when you run XBoard in ICS mode, it will connect to the ICS by
using `rsh' to run the command `telnet chessclub.com 5000' on host
`rsh.example.com'.
Suppose that you can telnet anywhere you want, but you have to run a
special program called `ptelnet' to do so.
First, we'll consider the easy case, in which `ptelnet chessclub.com
5000' gets you to the chess server. In this case set command line
options as follows:
xboard -ics -telnet -telnetProgram ptelnet
Then when you run XBoard in ICS mode, it will issue the command
`ptelnet chessclub.com 5000' to connect to the ICS.
Next, suppose that `ptelnet chessclub.com 5000' doesn't work; that is,
your `ptelnet' program doesn't let you connect to alternative ports.
As noted above, your chess server may allow you to connect on port 23
instead. In that case, just add the option `-icsport ""' to the above
command. But if your chess server doesn't let you connect on port 23,
you will have to find some other host outside the firewall and hop
through it. For instance, suppose you have a shell account at
`foo.edu'. Set command line options as follows:
xboard -ics -telnet -telnetProgram ptelnet -icshost foo.edu -icsport ""
Then when you run XBoard in ICS mode, it will issue the command
`ptelnet foo.edu' to connect to your account at `foo.edu'. Log in
there, then type `telnet chessclub.com 5000'.
ICC timestamp and FICS timeseal do not work through some firewalls.
You can use them only if your firewall gives a clean TCP connection
with a full 8-bit wide path. If your firewall allows you to get out
only by running a special telnet program, you can't use timestamp or
timeseal across it. But if you have access to a computer just outside
your firewall, and you have much lower netlag when talking to that
computer than to the ICS, it might be worthwhile running timestamp
there. Follow the instructions above for hopping through a host
outside the firewall (foo.edu in the example), but run timestamp or
timeseal on that host instead of telnet.
Suppose that you have a SOCKS firewall that will give you a clean 8-
bit wide TCP connection to the chess server, but only after you
authenticate yourself via the SOCKS protocol. In that case, you could
make a socksified version of XBoard and run that. If you are using
timestamp or timeseal, you will to socksify it, not XBoard; this may
be difficult seeing that ICC and FICS do not provide source code for
these programs. Socksification is beyond the scope of this document,
- 81 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
but see the SOCKS Web site at http://www.socks.permeo.com/. If you
are missing SOCKS, try http://www.funbureau.com/.
ENVIRONMENT VARIABLES
Game and position files are found in a directory named by the
`CHESSDIR' environment variable. If this variable is not set, the
current working directory is used. If `CHESSDIR' is set, XBoard
actually changes its working directory to `$CHESSDIR', so any files
written by the chess engine will be placed there too.
LIMITATIONS AND KNOWN BUGS
There is no way for two people running copies of XBoard to play each
other without going through an Internet Chess Server.
Under some circumstances, your ICS password may be echoed when you log
on.
If you are connecting to the ICS by running telnet on an Internet
provider or firewall host, you may find that each line you type is
echoed back an extra time after you hit <Enter>. If your Internet
provider is a Unix system, you can probably turn its echo off by
typing `stty -echo' after you log in, and/or typing <^E><Enter>
(Ctrl+E followed by the Enter key) to the telnet program after you
have logged into ICS. It is a good idea to do this if you can,
because the extra echo can occasionally confuse XBoard's parsing
routines.
The game parser recognizes only algebraic notation.
Many of the following points used to be limitations in XBoard 4.2.7
and earlier, but are now fixed: The internal move legality tester in
XBoard 4.3.xx does look at the game history, and is fully aware of
castling or en-passant-capture rights. It permits castling with the
king on the d file because this is possible in some "wild 1" games on
ICS. The piece-drop menu does not check piece drops in bughouse to see
if you actually hold the piece you are trying to drop. But this way of
dropping pieces should be considered an obsolete feature, now that
pieces can be dropped by dragging them from the holdings to the board.
Anyway, if you would attempt an illegal move when using a chess engine
or the ICS, XBoard will accept the error message that comes back, undo
the move, and let you try another. FEN positions saved by XBoard do
include correct information about whether castling or en passant are
legal, and also handle the 50-move counter. The mate detector does
not understand that non-contact mate is not really mate in bughouse.
The only problem this causes while playing is minor: a "#" (mate
indicator) character will show up after a non-contact mating move in
the move list. XBoard will not assume the game is over at that point,
not even when the option Detect Mates is on. Edit Game mode always
uses the rules of the selected variant, which can be a variant that
- 82 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
uses piece drops. You can load and edit games that contain piece
drops. The (obsolete) piece menus are not active, but you can perform
piece drops by dragging pieces from the holdings. Fischer Random
castling is fully understood. You can enter castlings by dragging the
King on top of your Rook. You can probably also play Fischer Random
successfully on ICS by typing castling moves into the ICS Interaction
window.
The menus may not work if your keyboard is in Caps Lock or Num Lock
mode. This seems to be a problem with the Athena menu widget, not an
XBoard bug.
Also see the ToDo file included with the distribution for many other
possible bugs, limitations, and ideas for improvement that have been
suggested.
REPORTING PROBLEMS
You can report bugs and problems with XBoard using the bug tracker at
`https://savannah.gnu.org/projects/xboard/' or by sending mail to
`<bug-xboard@gnu.org>'. It can also be useful to report or discuss
bugs in the WinBoard Forum at `http://www.open-aurec.com/wbforum/',
WinBoard development section.
Please use the `script' program to start a typescript, run XBoard with
the `-debug' option, and include the typescript output in your
message. Also tell us what kind of machine and what operating system
version you are using. The command `uname -a' will often tell you
this.
If you improve XBoard, please send a message about your changes, and
we will get in touch with you about merging them in to the main line
of development.
AUTHORS AND CONTRIBUTORS
Chris Sears and Dan Sears wrote the original XBoard. They were
responsible for versions 1.0 through 1.2. The color scheme was taken
from Wayne Christopher's `XChess' program.
Tim Mann was primarily responsible for XBoard versions 1.3 through
4.2.7, and for WinBoard (a port of XBoard to Microsoft Win32) from its
inception through version 4.2.7.
John Chanak contributed the initial implementation of ICS mode. Evan
Welsh wrote `CMail', and Patrick Surry helped in designing, testing,
and documenting it. Elmar Bartel contributed the new piece bitmaps
introduced in version 3.2. Jochen Wiedmann converted the
documentation to texinfo. Frank McIngvale added click/click moving,
the Analysis modes, piece flashing, ZIICS import, and ICS text
colorization to XBoard. Hugh Fisher added animated piece movement to
XBoard, and Henrik Gram added it to WinBoard. Mark Williams
- 83 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
contributed the initial (WinBoard-only) implementation of many new
features added to both XBoard and WinBoard in version 4.1.0, including
copy/paste, premove, icsAlarm, autoFlipView, training mode, auto
raise, and blindfold. Ben Nye contributed X copy/paste code for
XBoard.
In a fork from version 4.2.7, Alessandro Scotti added many elements to
the user interface of WinBoard, including the board textures and
font-based rendering, the evaluation-graph, move-history and engine-
output window. He was also responsible for adding the UCI support.
H. G. Muller continued this fork of the project, producing version
4.3. He made WinBoard castling- and e.p.-aware, added variant support
with adjustable board sizes, the crazyhouse holdings, and the fairy
pieces. In addition he added most of the adjudication options, made
WinBoard more robust in dealing with buggy and crashing engines, and
extended time control with a time-odds and node-count-based modes.
Most of the options that initially were WinBoard only have now been
back-ported to XBoard.
Michel van den Bergh provided the code for reading Polyglot opening
books.
Meanwhile, some work continued on the GNU XBoard project maintained at
savannah.gnu.org, but version 4.2.8 was never released. Daniel
Mehrmann was responsible for much of this work.
Most recently, Arun Persaud worked with H. G. Muller to merge all the
features of the never-released XBoard/WinBoard 4.2.8 of the GNU XBoard
project and the never-released 4.3.16 from H. G.'s fork into a unified
XBoard/WinBoard 4.4, which is now available both from the
savannah.gnu.org web site and the WinBoard forum.
CMAIL
The `cmail' program can help you play chess by email with opponents of
your choice using XBoard as an interface.
You will usually run `cmail' without giving any options.
CMail options
-h Displays `cmail' usage information.
-c Shows the conditions of the GNU General Public License. See
Copying.
-w Shows the warranty notice of the GNU General Public License. See
Copying.
- 84 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
-v
-xv Provides or inhibits verbose output from `cmail' and XBoard,
useful for debugging. The `-xv' form also inhibits the cmail
introduction message.
-mail
-xmail
Invokes or inhibits the sending of a mail message containing the
move.
-xboard
-xxboard
Invokes or inhibits the running of XBoard on the game file.
-reuse
-xreuse
Invokes or inhibits the reuse of an existing XBoard to display
the current game.
-remail
Resends the last mail message for that game. This inhibits
running XBoard.
-game <name>
The name of the game to be processed.
-wgames <number>
-bgames <number>
-games <number>
Number of games to start as White, as Black or in total. Default
is 1 as white and none as black. If only one color is specified
then none of the other color is assumed. If no color is specified
then equal numbers of White and Black games are started, with the
extra game being as White if an odd number of total games is
specified.
-me <short name>
-opp <short name>
A one-word alias for yourself or your opponent.
-wname <full name>
-bname <full name>
-myname <full name>
-oppname <full name>
The full name of White, Black, yourself or your opponent.
-wna <net address>
-bna <net address>
-na <net address>
-oppna <net address>
The email address of White, Black, yourself or your opponent.
- 85 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
-dir <directory>
The directory in which `cmail' keeps its files. This defaults to
the environment variable `$CMAIL_DIR' or failing that,
`$CHESSDIR', `$HOME/Chess' or `~/Chess'. It will be created if it
does not exist.
-arcdir <directory>
The directory in which `cmail' archives completed games. Defaults
to the environment variable `$CMAIL_ARCDIR' or, in its absence,
the same directory as cmail keeps its working files (above).
-mailprog <mail program>
The program used by cmail to send email messages. This defaults
to the environment variable `$CMAIL_MAILPROG' or failing that
`/usr/ucb/Mail', `/usr/ucb/mail' or `Mail'. You will need to set
this variable if none of the above paths fit your system.
-logFile <file>
A file in which to dump verbose debugging messages that are
invoked with the `-v' option.
-event <event>
The PGN Event tag (default `Email correspondence game').
-site <site>
The PGN Site tag (default `NET').
-round <round>
The PGN Round tag (default `-', not applicable).
-mode <mode>
The PGN Mode tag (default `EM', Electronic Mail).
Other options
Any option flags not listed above are passed through to XBoard.
Invoking XBoard through CMail changes the default values of two
XBoard options: The default value for `-noChessProgram' is
changed to true; that is, by default no chess engine is started.
The default value for `-timeDelay' is changed to 0; that is, by
default XBoard immediately goes to the end of the game as played
so far, rather than stepping through the moves one by one. You
can still set these options to whatever values you prefer by
supplying them on CMail's command line. See Options.
Starting a CMail Game
Type `cmail' from a shell to start a game as white. After an opening
message, you will be prompted for a game name, which is optional -- if
you simply press <Enter>, the game name will take the form `you-VS-
opponent'. You will next be prompted for the short name of your
opponent. If you haven't played this person before, you will also be
prompted for his/her email address. `cmail' will then invoke XBoard in
- 86 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
the background. Make your first move and select `Mail Move' from the
`File' menu. See File Menu. If all is well, `cmail' will mail a copy
of the move to your opponent. If you select `Exit' without having
selected `Mail Move' then no move will be made.
Answering a Move
When you receive a message from an opponent containing a move in one
of your games, simply pipe the message through `cmail'. In some
mailers this is as simple as typing `| cmail' when viewing the
message, while in others you may have to save the message to a file
and do `cmail < file' at the command line. In either case `cmail' will
display the game using XBoard. If you didn't exit XBoard when you made
your first move then `cmail' will do its best to use the existing
XBoard instead of starting a new one. As before, simply make a move
and select `Mail Move' from the `File' menu. See File Menu. `cmail'
will try to use the XBoard that was most recently used to display the
current game. This means that many games can be in progress
simultaneously, each with its own active XBoard.
If you want to look at the history or explore a variation, go ahead,
but you must return to the current position before XBoard will allow
you to mail a move. If you edit the game's history you must select
`Reload Same Game' from the `File' menu to get back to the original
position, then make the move you want and select `Mail Move'. As
before, if you decide you aren't ready to make a move just yet you can
either select `Exit' without sending a move or just leave XBoard
running until you are ready.
Multi-Game Messages
It is possible to have a `cmail' message carry more than one game.
This feature was implemented to handle IECG (International Email Chess
Group) matches, where a match consists of one game as white and one as
black, with moves transmitted simultaneously. In case there are more
general uses, `cmail' itself places no limit on the number of
black/white games contained in a message; however, XBoard does.
Completing a Game
Because XBoard can detect checkmate and stalemate, `cmail' handles
game termination sensibly. As well as resignation, the `Action' menu
allows draws to be offered and accepted for `cmail' games.
For multi-game messages, only unfinished and just-finished games will
be included in email messages. When all the games are finished, they
are archived in the user's archive directory, and similarly in the
opponent's when he or she pipes the final message through `cmail'. The
archive file name includes the date the game was started.
- 87 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
Known CMail Problems
It's possible that a strange conjunction of conditions may
occasionally mean that `cmail' has trouble reactivating an existing
XBoard. If this should happen, simply trying it again should work. If
not, remove the file that stores the XBoard's PID (`game.pid') or use
the `-xreuse' option to force `cmail' to start a new XBoard.
Versions of `cmail' after 2.16 no longer understand the old file
format that XBoard used to use and so cannot be used to correspond
with anyone using an older version.
Versions of `cmail' older than 2.11 do not handle multi-game messages,
so multi-game correspondence is not possible with opponents using an
older version.
OTHER PROGRAMS YOU CAN USE WITH
Here are some other programs you can use with XBoard
GNU Chess
The GNU Chess engine is available from:
ftp://ftp.gnu.org/gnu/gnuchess/
You can use XBoard to play a game against GNU Chess, or to interface
GNU Chess to an ICS.
Fairy-Max
Fairy-Max is a derivative from the once World's smallest Chess program
micro-Max, which measures only about 100 lines of source code. The
main difference with micro-Max is that Fairy-Max loads its move-
generator tables from a file, so that the rules for piece movement can
be easily configured to implement unorthodox pieces. Fairy-Max can
therefore play a large number of variants, normal Chess being one of
those. In addition it plays Knightmate, Capablanca and Gothic Chess,
Shatranj, Courier Chess, Cylinder chess, Berolina Chess, while the
user can easily define new variants. It can be obtained from:
http://home.hccnet.nl/h.g.muller/dwnldpage.html
HoiChess
HoiChess is a not-so-very-strong Chess engine, which comes with a
derivative HoiXiangqi, able to play Chinese Chess. It can be obtained
from the standard Linux repositories through:
sudo apt-get install hoichess
- 88 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
Crafty
Crafty is a chess engine written by Bob Hyatt. You can use XBoard to
play a game against Crafty, hook Crafty up to an ICS, or use Crafty to
interactively analyze games and positions for you.
Crafty is a strong, rapidly evolving chess program. This rapid pace of
development is good, because it means Crafty is always getting better.
This can sometimes cause problems with backwards compatibility, but
usually the latest version of Crafty will work well with the latest
version of XBoard. Crafty can be obtained from its author's FTP site:
ftp://ftp.cis.uab.edu/hyatt/.
To use Crafty with XBoard, give the -fcp and -fd options as follows,
where <crafty's directory> is the directory in which you installed
Crafty and placed its book and other support files.
COPYRIGHT
Copyright (C) 1991 Digital Equipment Corporation, Maynard,
Massachusetts.
All Rights Reserved.
Permission to use, copy, modify, and distribute this software and its
documentation for any purpose and without fee is hereby granted,
provided that the above copyright notice appear in all copies and that
both that copyright notice and this permission notice appear in
supporting documentation, and that the name of Digital not be used in
advertising or publicity pertaining to distribution of the software
without specific, written prior permission.
Digital disclaims all warranties with regard to this software,
including all implied warranties of merchantability and fitness. In
no event shall Digital be liable for any special, indirect or
consequential damages or any damages whatsoever resulting from loss of
use, data or profits, whether in an action of contract, negligence or
other tortious action, arising out of or in connection with the use or
performance of this software.
Enhancements copyright (C) 1992-2003, 2004, 2005, 2006, 2007, 2008,
2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016 Free Software
Foundation, Inc.
Published by the Free Software Foundation
59 Temple Place - Suite 330
Boston, MA 02111-1307 USA
Permission is granted to make and distribute verbatim copies of this
manual provided the copyright notice and this permission notice are
preserved on all copies.
- 89 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
Permission is granted to copy and distribute modified versions of this
manual under the conditions for verbatim copying, provided also that
the section entitled ``GNU General Public License,'' is included
exactly as in the original, and provided that the entire resulting
derived work is distributed under the terms of a permission notice
identical to this one.
Permission is granted to copy and distribute translations of this
manual into another language, under the above conditions for modified
versions, except that the section entitled ``GNU General Public
License,'' and this permission notice, may be included in translations
approved by the Free Software Foundation instead of in the original
English.
GNU GENERAL PUBLIC LICENSE
Copyright (C) 2007 Free Software Foundation, Inc. `http://fsf.org/'
Everyone is permitted to copy and distribute verbatim copies of this
license document, but changing it is not allowed.
The GNU General Public License is a free, copyleft license for
software and other kinds of works.
The licenses for most software and other practical works are designed
to take away your freedom to share and change the works. By contrast,
the GNU General Public License is intended to guarantee your freedom
to share and change all versions of a program -- to make sure it
remains free software for all its users. We, the Free Software
Foundation, use the GNU General Public License for most of our
software; it applies also to any other work released this way by its
authors. You can apply it to your programs, too.
When we speak of free software, we are referring to freedom, not
price. Our General Public Licenses are designed to make sure that you
have the freedom to distribute copies of free software (and charge for
them if you wish), that you receive source code or can get it if you
want it, that you can change the software or use pieces of it in new
free programs, and that you know you can do these things.
To protect your rights, we need to prevent others from denying you
these rights or asking you to surrender the rights. Therefore, you
have certain responsibilities if you distribute copies of the
software, or if you modify it: responsibilities to respect the freedom
of others.
For example, if you distribute copies of such a program, whether
gratis or for a fee, you must pass on to the recipients the same
freedoms that you received. You must make sure that they, too,
receive or can get the source code. And you must show them these
terms so they know their rights.
- 90 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
Developers that use the GNU GPL protect your rights with two steps:
(1) assert copyright on the software, and (2) offer you this License
giving you legal permission to copy, distribute and/or modify it.
For the developers' and authors' protection, the GPL clearly explains
that there is no warranty for this free software. For both users' and
authors' sake, the GPL requires that modified versions be marked as
changed, so that their problems will not be attributed erroneously to
authors of previous versions.
Some devices are designed to deny users access to install or run
modified versions of the software inside them, although the
manufacturer can do so. This is fundamentally incompatible with the
aim of protecting users' freedom to change the software. The
systematic pattern of such abuse occurs in the area of products for
individuals to use, which is precisely where it is most unacceptable.
Therefore, we have designed this version of the GPL to prohibit the
practice for those products. If such problems arise substantially in
other domains, we stand ready to extend this provision to those
domains in future versions of the GPL, as needed to protect the
freedom of users.
Finally, every program is threatened constantly by software patents.
States should not allow patents to restrict development and use of
software on general-purpose computers, but in those that do, we wish
to avoid the special danger that patents applied to a free program
could make it effectively proprietary. To prevent this, the GPL
assures that patents cannot be used to render the program non-free.
The precise terms and conditions for copying, distribution and
modification follow.
Definitions.
``This License'' refers to version 3 of the GNU General Public
License.
``Copyright'' also means copyright-like laws that apply to other
kinds of works, such as semiconductor masks.
``The Program'' refers to any copyrightable work licensed under
this License. Each licensee is addressed as ``you''.
``Licensees'' and ``recipients'' may be individuals or
organizations.
To ``modify'' a work means to copy from or adapt all or part of
the work in a fashion requiring copyright permission, other than
the making of an exact copy. The resulting work is called a
``modified version'' of the earlier work or a work ``based on''
the earlier work.
- 91 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
A ``covered work'' means either the unmodified Program or a work
based on the Program.
To ``propagate'' a work means to do anything with it that,
without permission, would make you directly or secondarily liable
for infringement under applicable copyright law, except executing
it on a computer or modifying a private copy. Propagation
includes copying, distribution (with or without modification),
making available to the public, and in some countries other
activities as well.
To ``convey'' a work means any kind of propagation that enables
other parties to make or receive copies. Mere interaction with a
user through a computer network, with no transfer of a copy, is
not conveying.
An interactive user interface displays ``Appropriate Legal
Notices'' to the extent that it includes a convenient and
prominently visible feature that (1) displays an appropriate
copyright notice, and (2) tells the user that there is no
warranty for the work (except to the extent that warranties are
provided), that licensees may convey the work under this License,
and how to view a copy of this License. If the interface
presents a list of user commands or options, such as a menu, a
prominent item in the list meets this criterion.
Source Code.
The ``source code'' for a work means the preferred form of the
work for making modifications to it. ``Object code'' means any
non-source form of a work.
A ``Standard Interface'' means an interface that either is an
official standard defined by a recognized standards body, or, in
the case of interfaces specified for a particular programming
language, one that is widely used among developers working in
that language.
The ``System Libraries'' of an executable work include anything,
other than the work as a whole, that (a) is included in the
normal form of packaging a Major Component, but which is not part
of that Major Component, and (b) serves only to enable use of the
work with that Major Component, or to implement a Standard
Interface for which an implementation is available to the public
in source code form. A ``Major Component'', in this context,
means a major essential component (kernel, window system, and so
on) of the specific operating system (if any) on which the
executable work runs, or a compiler used to produce the work, or
an object code interpreter used to run it.
The ``Corresponding Source'' for a work in object code form means
- 92 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
all the source code needed to generate, install, and (for an
executable work) run the object code and to modify the work,
including scripts to control those activities. However, it does
not include the work's System Libraries, or general-purpose tools
or generally available free programs which are used unmodified in
performing those activities but which are not part of the work.
For example, Corresponding Source includes interface definition
files associated with source files for the work, and the source
code for shared libraries and dynamically linked subprograms that
the work is specifically designed to require, such as by intimate
data communication or control flow between those subprograms and
other parts of the work.
The Corresponding Source need not include anything that users can
regenerate automatically from other parts of the Corresponding
Source.
The Corresponding Source for a work in source code form is that
same work.
Basic Permissions.
All rights granted under this License are granted for the term of
copyright on the Program, and are irrevocable provided the stated
conditions are met. This License explicitly affirms your
unlimited permission to run the unmodified Program. The output
from running a covered work is covered by this License only if
the output, given its content, constitutes a covered work. This
License acknowledges your rights of fair use or other equivalent,
as provided by copyright law.
You may make, run and propagate covered works that you do not
convey, without conditions so long as your license otherwise
remains in force. You may convey covered works to others for the
sole purpose of having them make modifications exclusively for
you, or provide you with facilities for running those works,
provided that you comply with the terms of this License in
conveying all material for which you do not control copyright.
Those thus making or running the covered works for you must do so
exclusively on your behalf, under your direction and control, on
terms that prohibit them from making any copies of your
copyrighted material outside their relationship with you.
Conveying under any other circumstances is permitted solely under
the conditions stated below. Sublicensing is not allowed;
section 10 makes it unnecessary.
Protecting Users' Legal Rights From Anti-Circumvention
No covered work shall be deemed part of an effective
technological measure under any applicable law fulfilling
- 93 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
obligations under article 11 of the WIPO copyright treaty adopted
on 20 December 1996, or similar laws prohibiting or restricting
circumvention of such measures.
When you convey a covered work, you waive any legal power to
forbid circumvention of technological measures to the extent such
circumvention is effected by exercising rights under this License
with respect to the covered work, and you disclaim any intention
to limit operation or modification of the work as a means of
enforcing, against the work's users, your or third parties' legal
rights to forbid circumvention of technological measures.
Conveying Verbatim Copies.
You may convey verbatim copies of the Program's source code as
you receive it, in any medium, provided that you conspicuously
and appropriately publish on each copy an appropriate copyright
notice; keep intact all notices stating that this License and any
non-permissive terms added in accord with section 7 apply to the
code; keep intact all notices of the absence of any warranty; and
give all recipients a copy of this License along with the
Program.
You may charge any price or no price for each copy that you
convey, and you may offer support or warranty protection for a
fee.
Conveying Modified Source Versions.
You may convey a work based on the Program, or the modifications
to produce it from the Program, in the form of source code under
the terms of section 4, provided that you also meet all of these
conditions:
The work must carry prominent notices stating that you modified
it, and giving a relevant date.
The work must carry prominent notices stating that it is released
under this License and any conditions added under section 7.
This requirement modifies the requirement in section 4 to ``keep
intact all notices''.
You must license the entire work, as a whole, under this License
to anyone who comes into possession of a copy. This License will
therefore apply, along with any applicable section 7 additional
terms, to the whole of the work, and all its parts, regardless of
how they are packaged. This License gives no permission to
license the work in any other way, but it does not invalidate
such permission if you have separately received it.
If the work has interactive user interfaces, each must display
- 94 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
Appropriate Legal Notices; however, if the Program has
interactive interfaces that do not display Appropriate Legal
Notices, your work need not make them do so.
A compilation of a covered work with other separate and
independent works, which are not by their nature extensions of
the covered work, and which are not combined with it such as to
form a larger program, in or on a volume of a storage or
distribution medium, is called an ``aggregate'' if the
compilation and its resulting copyright are not used to limit the
access or legal rights of the compilation's users beyond what the
individual works permit. Inclusion of a covered work in an
aggregate does not cause this License to apply to the other parts
of the aggregate.
Conveying Non-Source Forms.
You may convey a covered work in object code form under the terms
of sections 4 and 5, provided that you also convey the machine-
readable Corresponding Source under the terms of this License, in
one of these ways:
Convey the object code in, or embodied in, a physical product
(including a physical distribution medium), accompanied by the
Corresponding Source fixed on a durable physical medium
customarily used for software interchange.
Convey the object code in, or embodied in, a physical product
(including a physical distribution medium), accompanied by a
written offer, valid for at least three years and valid for as
long as you offer spare parts or customer support for that
product model, to give anyone who possesses the object code
either (1) a copy of the Corresponding Source for all the
software in the product that is covered by this License, on a
durable physical medium customarily used for software
interchange, for a price no more than your reasonable cost of
physically performing this conveying of source, or (2) access to
copy the Corresponding Source from a network server at no charge.
Convey individual copies of the object code with a copy of the
written offer to provide the Corresponding Source. This
alternative is allowed only occasionally and noncommercially, and
only if you received the object code with such an offer, in
accord with subsection 6b.
Convey the object code by offering access from a designated place
(gratis or for a charge), and offer equivalent access to the
Corresponding Source in the same way through the same place at no
further charge. You need not require recipients to copy the
Corresponding Source along with the object code. If the place to
copy the object code is a network server, the Corresponding
- 95 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
Source may be on a different server (operated by you or a third
party) that supports equivalent copying facilities, provided you
maintain clear directions next to the object code saying where to
find the Corresponding Source. Regardless of what server hosts
the Corresponding Source, you remain obligated to ensure that it
is available for as long as needed to satisfy these requirements.
Convey the object code using peer-to-peer transmission, provided
you inform other peers where the object code and Corresponding
Source of the work are being offered to the general public at no
charge under subsection 6d.
A separable portion of the object code, whose source code is
excluded from the Corresponding Source as a System Library, need
not be included in conveying the object code work.
A ``User Product'' is either (1) a ``consumer product'', which
means any tangible personal property which is normally used for
personal, family, or household purposes, or (2) anything designed
or sold for incorporation into a dwelling. In determining
whether a product is a consumer product, doubtful cases shall be
resolved in favor of coverage. For a particular product received
by a particular user, ``normally used'' refers to a typical or
common use of that class of product, regardless of the status of
the particular user or of the way in which the particular user
actually uses, or expects or is expected to use, the product. A
product is a consumer product regardless of whether the product
has substantial commercial, industrial or non-consumer uses,
unless such uses represent the only significant mode of use of
the product.
``Installation Information'' for a User Product means any
methods, procedures, authorization keys, or other information
required to install and execute modified versions of a covered
work in that User Product from a modified version of its
Corresponding Source. The information must suffice to ensure
that the continued functioning of the modified object code is in
no case prevented or interfered with solely because modification
has been made.
If you convey an object code work under this section in, or with,
or specifically for use in, a User Product, and the conveying
occurs as part of a transaction in which the right of possession
and use of the User Product is transferred to the recipient in
perpetuity or for a fixed term (regardless of how the transaction
is characterized), the Corresponding Source conveyed under this
section must be accompanied by the Installation Information. But
this requirement does not apply if neither you nor any third
party retains the ability to install modified object code on the
User Product (for example, the work has been installed in ROM).
- 96 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
The requirement to provide Installation Information does not
include a requirement to continue to provide support service,
warranty, or updates for a work that has been modified or
installed by the recipient, or for the User Product in which it
has been modified or installed. Access to a network may be
denied when the modification itself materially and adversely
affects the operation of the network or violates the rules and
protocols for communication across the network.
Corresponding Source conveyed, and Installation Information
provided, in accord with this section must be in a format that is
publicly documented (and with an implementation available to the
public in source code form), and must require no special password
or key for unpacking, reading or copying.
Additional Terms.
``Additional permissions'' are terms that supplement the terms of
this License by making exceptions from one or more of its
conditions. Additional permissions that are applicable to the
entire Program shall be treated as though they were included in
this License, to the extent that they are valid under applicable
law. If additional permissions apply only to part of the
Program, that part may be used separately under those
permissions, but the entire Program remains governed by this
License without regard to the additional permissions.
When you convey a copy of a covered work, you may at your option
remove any additional permissions from that copy, or from any
part of it. (Additional permissions may be written to require
their own removal in certain cases when you modify the work.)
You may place additional permissions on material, added by you to
a covered work, for which you have or can give appropriate
copyright permission.
Notwithstanding any other provision of this License, for material
you add to a covered work, you may (if authorized by the
copyright holders of that material) supplement the terms of this
License with terms:
Disclaiming warranty or limiting liability differently from the
terms of sections 15 and 16 of this License; or
Requiring preservation of specified reasonable legal notices or
author attributions in that material or in the Appropriate Legal
Notices displayed by works containing it; or
Prohibiting misrepresentation of the origin of that material, or
requiring that modified versions of such material be marked in
reasonable ways as different from the original version; or
- 97 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
Limiting the use for publicity purposes of names of licensors or
authors of the material; or
Declining to grant rights under trademark law for use of some
trade names, trademarks, or service marks; or
Requiring indemnification of licensors and authors of that
material by anyone who conveys the material (or modified versions
of it) with contractual assumptions of liability to the
recipient, for any liability that these contractual assumptions
directly impose on those licensors and authors.
All other non-permissive additional terms are considered
``further restrictions'' within the meaning of section 10. If
the Program as you received it, or any part of it, contains a
notice stating that it is governed by this License along with a
term that is a further restriction, you may remove that term. If
a license document contains a further restriction but permits
relicensing or conveying under this License, you may add to a
covered work material governed by the terms of that license
document, provided that the further restriction does not survive
such relicensing or conveying.
If you add terms to a covered work in accord with this section,
you must place, in the relevant source files, a statement of the
additional terms that apply to those files, or a notice
indicating where to find the applicable terms.
Additional terms, permissive or non-permissive, may be stated in
the form of a separately written license, or stated as
exceptions; the above requirements apply either way.
Termination.
You may not propagate or modify a covered work except as
expressly provided under this License. Any attempt otherwise to
propagate or modify it is void, and will automatically terminate
your rights under this License (including any patent licenses
granted under the third paragraph of section 11).
However, if you cease all violation of this License, then your
license from a particular copyright holder is reinstated (a)
provisionally, unless and until the copyright holder explicitly
and finally terminates your license, and (b) permanently, if the
copyright holder fails to notify you of the violation by some
reasonable means prior to 60 days after the cessation.
Moreover, your license from a particular copyright holder is
reinstated permanently if the copyright holder notifies you of
the violation by some reasonable means, this is the first time
you have received notice of violation of this License (for any
- 98 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
work) from that copyright holder, and you cure the violation
prior to 30 days after your receipt of the notice.
Termination of your rights under this section does not terminate
the licenses of parties who have received copies or rights from
you under this License. If your rights have been terminated and
not permanently reinstated, you do not qualify to receive new
licenses for the same material under section 10.
Acceptance Not Required for Having Copies.
You are not required to accept this License in order to receive
or run a copy of the Program. Ancillary propagation of a covered
work occurring solely as a consequence of using peer-to-peer
transmission to receive a copy likewise does not require
acceptance. However, nothing other than this License grants you
permission to propagate or modify any covered work. These
actions infringe copyright if you do not accept this License.
Therefore, by modifying or propagating a covered work, you
indicate your acceptance of this License to do so.
Automatic Licensing of Downstream Recipients.
Each time you convey a covered work, the recipient automatically
receives a license from the original licensors, to run, modify
and propagate that work, subject to this License. You are not
responsible for enforcing compliance by third parties with this
License.
An ``entity transaction'' is a transaction transferring control
of an organization, or substantially all assets of one, or
subdividing an organization, or merging organizations. If
propagation of a covered work results from an entity transaction,
each party to that transaction who receives a copy of the work
also receives whatever licenses to the work the party's
predecessor in interest had or could give under the previous
paragraph, plus a right to possession of the Corresponding Source
of the work from the predecessor in interest, if the predecessor
has it or can get it with reasonable efforts.
You may not impose any further restrictions on the exercise of
the rights granted or affirmed under this License. For example,
you may not impose a license fee, royalty, or other charge for
exercise of rights granted under this License, and you may not
initiate litigation (including a cross-claim or counterclaim in a
lawsuit) alleging that any patent claim is infringed by making,
using, selling, offering for sale, or importing the Program or
any portion of it.
- 99 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
Patents.
A ``contributor'' is a copyright holder who authorizes use under
this License of the Program or a work on which the Program is
based. The work thus licensed is called the contributor's
``contributor version''.
A contributor's ``essential patent claims'' are all patent claims
owned or controlled by the contributor, whether already acquired
or hereafter acquired, that would be infringed by some manner,
permitted by this License, of making, using, or selling its
contributor version, but do not include claims that would be
infringed only as a consequence of further modification of the
contributor version. For purposes of this definition,
``control'' includes the right to grant patent sublicenses in a
manner consistent with the requirements of this License.
Each contributor grants you a non-exclusive, worldwide, royalty-
free patent license under the contributor's essential patent
claims, to make, use, sell, offer for sale, import and otherwise
run, modify and propagate the contents of its contributor
version.
In the following three paragraphs, a ``patent license'' is any
express agreement or commitment, however denominated, not to
enforce a patent (such as an express permission to practice a
patent or covenant not to sue for patent infringement). To
``grant'' such a patent license to a party means to make such an
agreement or commitment not to enforce a patent against the
party.
If you convey a covered work, knowingly relying on a patent
license, and the Corresponding Source of the work is not
available for anyone to copy, free of charge and under the terms
of this License, through a publicly available network server or
other readily accessible means, then you must either (1) cause
the Corresponding Source to be so available, or (2) arrange to
deprive yourself of the benefit of the patent license for this
particular work, or (3) arrange, in a manner consistent with the
requirements of this License, to extend the patent license to
downstream recipients. ``Knowingly relying'' means you have
actual knowledge that, but for the patent license, your conveying
the covered work in a country, or your recipient's use of the
covered work in a country, would infringe one or more
identifiable patents in that country that you have reason to
believe are valid.
If, pursuant to or in connection with a single transaction or
arrangement, you convey, or propagate by procuring conveyance of,
a covered work, and grant a patent license to some of the parties
receiving the covered work authorizing them to use, propagate,
modify or convey a specific copy of the covered work, then the
- 100 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
patent license you grant is automatically extended to all
recipients of the covered work and works based on it.
A patent license is ``discriminatory'' if it does not include
within the scope of its coverage, prohibits the exercise of, or
is conditioned on the non-exercise of one or more of the rights
that are specifically granted under this License. You may not
convey a covered work if you are a party to an arrangement with a
third party that is in the business of distributing software,
under which you make payment to the third party based on the
extent of your activity of conveying the work, and under which
the third party grants, to any of the parties who would receive
the covered work from you, a discriminatory patent license (a) in
connection with copies of the covered work conveyed by you (or
copies made from those copies), or (b) primarily for and in
connection with specific products or compilations that contain
the covered work, unless you entered into that arrangement, or
that patent license was granted, prior to 28 March 2007.
Nothing in this License shall be construed as excluding or
limiting any implied license or other defenses to infringement
that may otherwise be available to you under applicable patent
law.
No Surrender of Others' Freedom.
If conditions are imposed on you (whether by court order,
agreement or otherwise) that contradict the conditions of this
License, they do not excuse you from the conditions of this
License. If you cannot convey a covered work so as to satisfy
simultaneously your obligations under this License and any other
pertinent obligations, then as a consequence you may not convey
it at all. For example, if you agree to terms that obligate you
to collect a royalty for further conveying from those to whom you
convey the Program, the only way you could satisfy both those
terms and this License would be to refrain entirely from
conveying the Program.
Use with the GNU Affero General
Notwithstanding any other provision of this License, you have
permission to link or combine any covered work with a work
licensed under version 3 of the GNU Affero General Public License
into a single combined work, and to convey the resulting work.
The terms of this License will continue to apply to the part
which is the covered work, but the special requirements of the
GNU Affero General Public License, section 13, concerning
interaction through a network will apply to the combination as
such.
- 101 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
Revised Versions of this License.
The Free Software Foundation may publish revised and/or new
versions of the GNU General Public License from time to time.
Such new versions will be similar in spirit to the present
version, but may differ in detail to address new problems or
concerns.
Each version is given a distinguishing version number. If the
Program specifies that a certain numbered version of the GNU
General Public License ``or any later version'' applies to it,
you have the option of following the terms and conditions either
of that numbered version or of any later version published by the
Free Software Foundation. If the Program does not specify a
version number of the GNU General Public License, you may choose
any version ever published by the Free Software Foundation.
If the Program specifies that a proxy can decide which future
versions of the GNU General Public License can be used, that
proxy's public statement of acceptance of a version permanently
authorizes you to choose that version for the Program.
Later license versions may give you additional or different
permissions. However, no additional obligations are imposed on
any author or copyright holder as a result of your choosing to
follow a later version.
Disclaimer of Warranty.
THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE
COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM ``AS
IS'' WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE
RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH
YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
Limitation of Liability.
IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN
WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO
MODIFIES AND/OR CONVEYS THE PROGRAM AS PERMITTED ABOVE, BE LIABLE
TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR
CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE
THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA
BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF
THE POSSIBILITY OF SUCH DAMAGES.
- 102 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
Interpretation of Sections 15 and 16.
If the disclaimer of warranty and limitation of liability
provided above cannot be given local legal effect according to
their terms, reviewing courts shall apply local law that most
closely approximates an absolute waiver of all civil liability in
connection with the Program, unless a warranty or assumption of
liability accompanies a copy of the Program in return for a fee.
If you develop a new program, and you want it to be of the
greatest possible use to the public, the best way to achieve this
is to make it free software which everyone can redistribute and
change under these terms.
To do so, attach the following notices to the program. It is
safest to attach them to the start of each source file to most
effectively state the exclusion of warranty; and each file should
have at least the ``copyright'' line and a pointer to where the
full notice is found.
ONE LINE TO GIVE THE PROGRAM'S NAME AND A BRIEF IDEA OF WHAT IT DOES.
Copyright (C) YEAR NAME OF AUTHOR
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or (at
your option) any later version.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see `http://www.gnu.org/licenses/'.
Also add information on how to contact you by electronic and
paper mail.
If the program does terminal interaction, make it output a short
notice like this when it starts in an interactive mode:
PROGRAM Copyright (C) YEAR NAME OF AUTHOR
This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
This is free software, and you are welcome to redistribute it
under certain conditions; type `show c' for details.
The hypothetical commands `show w' and `show c' should show the
appropriate parts of the General Public License. Of course, your
program's commands might be different; for a GUI interface, you
would use an ``about box''.
- 103 - Formatted: April 26, 2024
xboard(6) GNU xboard(6)
$Date:
You should also get your employer (if you work as a programmer)
or school, if any, to sign a ``copyright disclaimer'' for the
program, if necessary. For more information on this, and how to
apply and follow the GNU GPL, see `http://www.gnu.org/licenses/'.
The GNU General Public License does not permit incorporating your
program into proprietary programs. If your program is a
subroutine library, you may consider it more useful to permit
linking proprietary applications with the library. If this is
what you want to do, use the GNU Lesser General Public License
instead of this License. But first, please read
`http://www.gnu.org/philosophy/why-not-lgpl.html'.
- 104 - Formatted: April 26, 2024
