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 xearth(1)                           KLJ                           xearth(1)
                                November 1999



 NAME
      xearth - displays a shaded image of the Earth in an X window


 SYNOPSIS
      xearth [-proj proj_type ] [-pos pos_spec ] [-rot angle ] [-sunpos
      sun_pos_spec ] [-mag factor ] [-size size_spec ] [-shift shift_spec ]
      [-shade|-noshade] [-label|-nolabel] [-labelpos geom ]
      [-markers|-nomarkers] [-markerfile file ] [-showmarkers]
      [-stars|-nostars] [-starfreq frequency ] [-bigstars percent ]
      [-grid|-nogrid] [-grid1 grid1 ] [-grid2 grid2 ] [-day pct ] [-night pct
      ] [-term pct ] [-gamma gamma_value ] [-wait secs ] [-timewarp
      timewarp_factor ] [-time fixed_time ] [-onepix|-twopix] [-mono|-nomono]
      [-ncolors num_colors ] [-font font_name ] [-root|-noroot] [-geometry
      geom ] [-title title ] [-iconname iconname ] [-name name ]
      [-fork|-nofork] [-once|-noonce] [-nice priority ] [-gif] [-ppm]
      [-display dpyname ] [-version]


 DESCRIPTION
      Xearth sets the X root window to an image of the Earth, as seen from
      your favorite vantage point in space, correctly shaded for the current
      position of the Sun. By default, xearth updates the displayed image
      every five minutes. The time between updates can be changed with the
      -wait option (see below); updates can be disabled completely by using
      the -once option (see below).

      If desired, Xearth can be configured to create and render into its own
      top-level X window instead of the root window; see the -root, -noroot,
      and -geometry options (below). Finally, xearth can also render
      directly into PPM and GIF files instead of drawing into an X window;
      see the -ppm and -gif options (below).

      This man page documents version 1.1 of xearth.


 OPTIONS
      Xearth understands the following command line options (corresponding X
      resources can be found in the following section):


      -proj proj_type
           Specify the projection type xearth should use. Supported
           projection types are mercator, orthographic, and cylindrical;
           these can either be spelled out in full or abbreviated to merc,
           orth, or cyl, respectively. Xearth uses an orthographic
           projection by default.


      -pos pos_spec
           Specify the position from which the Earth should be viewed. The



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 xearth(1)                           KLJ                           xearth(1)
                                November 1999



           pos_spec (position specifier) consists of a keyword, possibly
           followed by additional arguments. Valid keywords are: fixed,
           sunrel, orbit, moon, and random. (If you're having problems
           getting xearth to accept a position specifier as a command line
           argument, make sure and read the comments about position
           specifier delimiters and using explicit quoting in the sixth
           paragraph following this one.)

           The position specifier keyword fixed should be followed by two
           arguments, interpreted as numerical values indicating the
           latitude and longitude (expressed in decimal degrees) of a
           viewing position that is fixed with respect to the Earth's
           surface. Positive and negative values of latitude correspond to
           positions north and south of the equator, respectively. Positive
           and negative values of longitude correspond to positions east and
           west of Greenwich, respectively.

           The position specifier keyword sunrel should be followed by two
           arguments, interpreted as numerical values indicating the offsets
           in latitude and longitude (expressed in decimal degrees) of a
           viewing position that is fixed with respect to the position of
           the Sun. Positive and negative values of latitude and longitude
           are interpreted as for the fixed keyword.

           The position specifier keyword orbit should be followed by two
           arguments, interpreted as numerical values indicating the period
           (in hours) and orbital inclination (in decimal degrees) of a
           simple circular orbit; the viewing position follows this orbit.
           Astute readers will surely note that these parameters are not
           sufficient to uniquely specify a single circular orbit. This
           problem is solved by limiting the space of possible orbits to
           those positioned over 0 degrees latitude, 0 degrees longitude at
           time zero (the Un*x epoch, see time(3)).

           The position specifier keyword moon should not be followed by any
           arguments. When this keyword is used, the viewing position is the
           current position of the moon, recalculated at each update.

           The position specifier keyword random should not be followed by
           any arguments. When this keyword is used, the viewing position is
           selected at random each time an update occurs.

           Components of a position specifier are delimited by either
           whitespace, forward slashes (/), or commas. Note that using
           whitespace to separate position specifier components when
           invoking xearth from a shell may require explicit quoting to
           ensure the entire position specifier is passed as a single
           argument. For example, if you want to use spaces to delimit
           components and are using a "typical" shell, you'd need to use
           something like:




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 xearth(1)                           KLJ                           xearth(1)
                                November 1999



               -pos "fixed 42.33 -71.08"

           or

               -pos 'fixed 42.33 -71.08'

           to make things work. If you'd rather not have to explicitly quote
           things, you can use forward slashes or commas instead of spaces
           to separate components, as shown below.

               -pos fixed,42.33,-71.08
               -pos fixed/42.33/-71.08

           If a position specifier is not provided, xearth uses a default
           position specifier of "sunrel 0 0" (such that the entire day side
           of the Earth is always visible).


      -rot angle
           Specify a rotated viewing position such that the north is not
           "straight up" in the center of the rendered image. The angle can
           be specified either as a numeric value or the keyword galactic.
           When angle is a numeric, it represents the number of degrees by
           which the image is to be rotated. Positive values of angle rotate
           the rendered image counterclockwise; negative values rotate the
           rendered image clockwise. The keyword galactic orients the image
           so that the galactic north is straight up: the sun is positioned
           somewhere on the plane passing through the horizontal center of
           the screen. The default value of angle is 0.


      -sunpos sun_pos_spec
           Specify a fixed point on the Earth's surface where the Sun is
           always directly overhead. The sun_pos_spec (Sun position
           specifier) consists of two components, both numerical values;
           these components are interpreted as the latitude and longitude
           (in decimal degrees) of the point where the Sun is directly
           overhead.

           The details provided for position specifiers (see above) about
           the interpretation of positive and negative latitude and
           longitude values and the characters used to delimit specifier
           components apply to Sun position specifiers as well.

           By default, xearth calculates the actual position of the Sun and
           updates this position with the progression of time.


      -mag factor
           Specify the magnification of the displayed image. When the
           orthographic projection is in use, the diameter of the rendered



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 xearth(1)                           KLJ                           xearth(1)
                                November 1999



           Earth image is factor times the shorter of the width and height
           of the image (see the -size option, below). For the mercator and
           cylindrical projections, the width of the rendered image is
           factor times the width of the image (see the -size option,
           below). The default magnification factor is 1.


      -size size_spec
           Specify the size of the image to be rendered. The size_spec (size
           specifier) consists of two components, both positive integers;
           these components are interpreted as the width and height (in
           pixels) of the image.

           The details provided for position specifiers (see above) about
           the characters used to delimit specifier components apply to size
           specifiers as well.

           When rendering into the X root window, these values default to
           the dimensions of the root window. When producing a PPM or GIF
           file instead of drawing in the X root window (see the -ppm and
           -gif options, below), both values default to 512.

           When rendering into its own top-level X window, any values
           specified using this option are ignored; dimensions for the top-
           level window can be specified using the -geometry option.


      -shift shift_spec
           Specify that the center of the rendered Earth image should be
           shifted by some amount from the center of the image. The
           shift_spec (shift specifier) consists of two components, both
           integers; these components are interpreted as the offsets (in
           pixels) in the X and Y directions.

           The details provided for position specifiers (see above) about
           the characters used to delimit specifier components apply to
           shift specifiers as well.

           By default, the center of the rendered Earth image is aligned
           with the center of the image.


      -shade | -noshade
           Enable/disable shading. When shading is enabled, the surface of
           the Earth is shaded according to the current position of the Sun
           (and the values provided for the -day, -night, and -term options,
           below). When shading is disabled, use flat colors (green and
           blue) to render land and water. Shading is enabled by default.






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 xearth(1)                           KLJ                           xearth(1)
                                November 1999



      -label | -nolabel
           Enable/disable labeling. If labeling is enabled and xearth is
           rendering into an X window, provide a label that indicates the
           current date and time and current viewing and sun positions. The
           position of the label can be controlled using the -labelpos
           option (see below). Labeling is disabled by default.


      -labelpos geom
           Specify where the label should be drawn. If labeling is enabled
           and xearth is rendering into an X window, geom is interpreted as
           the "position" part an X-style geometry specification (e.g., {+-
           }<xoffset>{+-}<yoffset>; positive and negative values of xoffset
           denote offsets from the left and right edges of the display,
           respectively; positive and negative values of yoffset denote
           offsets from the top and bottom edges of the display,
           respectively) indicating how the label should be positioned.  The
           label position defaults to "-5-5" (i.e., five pixels inside the
           lower right-hand corner of the display).


      -markers | -nomarkers
           Enable/disable markers. If markers are enabled and xearth is
           rendering into an X window, display small red circles and text
           labels indicating the location of interesting places on the
           Earth's surface. Markers are enabled by default.


      -markerfile file
           Specify a file from which user-defined marker data (locations and
           names) should be read. Each line in the marker data file consists
           of three required components: the latitude and longitude
           (expressed in decimal degrees) followed by the text of the label
           that should be used. Individual components are delimited by
           either whitespace, forward slashes (/), or commas. Components
           that need to include delimiter characters (e.g., a multi-word
           label) should be enclosed in double quotes. For example, a line
           in a typical marker data file might look something like:

               42.33 -71.08 "Boston, MA"    # USA

           Everything between a `#' character and the end of a line,
           inclusive, is a considered to be a comment. Blank lines and lines
           containing only comments are allowed.

           In addition to the three required components, xearth supports
           optional following "key=value" components. In this version of
           xearth, the only supported "key" is "align", which can be used to
           control where marker labels are drawn in relation to the marker
           proper. Supported alignment values are "left", "right", "above",
           and "below"; the default behavior (if no alignment is specified)



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 xearth(1)                           KLJ                           xearth(1)
                                November 1999



           is "align=right".

           The marker data file is reread every time xearth redraws an image
           into an X window. In this way, the marker positions and labels
           can be dynamic (e.g., given appropriate data sources, markers
           could be used to encode hurricane positions, where earthquakes
           have happened recently, temperatures at fixed locations, or other
           forms of "real-time" data).

           Xearth includes a built-in set of marker data for 76 major
           locations around the world. The built-in data can be selected by
           specifying "built-in" for the file argument; this is the default
           behavior. The built-in set of marker data can be examined either
           by using the -showmarkers option (see below) or by reading the
           BUILT-IN file included with the xearth source distribution (see
           OBTAINING THE XEARTH SOURCE DISTRIBUTION, below).


      -showmarkers
           This option indicates that xearth should load the marker data
           (whether built-in or user-specified), print a copy of it to
           standard out in a form suitable for use with the -markers option
           (see above), and then exit.


      -stars | -nostars
           Enable/disable stars. If stars are enabled, the black background
           of "space" is filled with a random pattern of "stars" (individual
           white pixels). The fraction of background pixels that are turned
           into stars can be controlled with the -starfreq option (see
           below). Stars are enabled by default.


      -starfreq frequency
           Set the density of the random star pattern (see -stars, above);
           frequency indicates the fraction of background pixels that should
           be turned into "stars". The default value of frequency is 0.002.


      -bigstars percent
           Set the percentage of double-width stars (see -stars, above); by
           default, all stars are a single pixel, but this option can be
           used to create some stars that are composed of two horizontal
           pixels.  This provides a slightly less uniform look to the "night
           sky".


      -grid | -nogrid
           Enable/disable the display of a longitude/latitude grid on the
           Earth's surface. The spacing of major grid lines and dots between
           major grid lines can be controlled with the -grid1 and -grid2



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 xearth(1)                           KLJ                           xearth(1)
                                November 1999



           options (see below). Grid display is disabled by default.


      -grid1 grid1
           Specify the spacing of major grid lines if grid display (see
           -grid, above) is enabled; major grid lines are drawn with a
           90/grid1 degree spacing. The default value for grid1 is 6,
           corresponding to 15 degrees between major grid lines.


      -grid2 grid2
           Specify the spacing of dots along major grid lines if grid
           display (see -grid, above) is enabled. Along the equator and
           lines of longitude, grid dots are drawn with a 90/(grid1 x grid2)
           degree spacing. The spacing of grid dots along parallels (lines
           of latitude) other than the equator is adjusted to keep the
           surface distance between grid dots approximately constant. The
           default value for grid2 is 15; combined with the default grid1
           value of 6, this corresponds to placing grid dots on a one degree
           spacing.


      -day pct
           Specify the brightness that should be used to shade the day side
           of the Earth when shading is enabled. Pct should be an integer
           between 0 and 100, inclusive, where 0 indicates total darkness
           and 100 indicates total illumination. This value defaults to 100.


      -night pct
           Specify the brightness that should be used to shade the night
           side of the Earth when shading is enabled. Pct should be an
           integer between 0 and 100, inclusive, where 0 indicates total
           darkness and 100 indicates total illumination. This value
           defaults to 5 (if this seems overly dark, you may want to
           double-check that appropriate gamma correction is being employed;
           see -gamma, below).


      -term pct
           Specify the shading discontinuity at the terminator (day/night
           line). Pct should be an integer between 0 and 100, inclusive. A
           value of x indicates that the shading should immediately jump x
           percent of the difference between day and night shading values
           (see -day and -night, above) when crossing from the night side to
           the day side of the terminator. Thus a value of 0 indicates no
           discontinuity (the original xearth behavior), and a value of 100
           yields a maximal discontinuity (such that the entire day side of
           the earth is shaded with the -day shading value). This value
           defaults to 1.




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 xearth(1)                           KLJ                           xearth(1)
                                November 1999



      -gamma gamma_value
           When xearth is rendering into an X window, adjust the colors
           xearth uses by a gamma value. Values less than 1.0 yield darker
           colors; values greater than 1.0 yield brighter colors. The
           default gamma_value is 1.0, appropriate for use on systems with
           built-in gamma correction. For systems without built-in gamma
           correction, appropriate gamma values are often in the 2.3 to 2.6
           range.

           See the GAMMA-TEST file included with the xearth source
           distribution for information about a simple test that allows you
           to directly estimate the gamma of your display system (see
           OBTAINING THE XEARTH SOURCE DISTRIBUTION, below).


      -wait secs
           When rendering into an X window, wait secs seconds between
           updates. This value defaults to 300 seconds (five minutes).


      -timewarp timewarp_factor
           Scale the apparent rate at which time progresses by
           timewarp_factor. The default value of timewarp_factor is 1.0.


      -time fixed_time
           Instead of using the current time to determine the "value" of
           time-dependent positions (e.g., the position the sun), use a
           particular fixed_time (expressed in seconds since the Un*x epoch
           (see time(3)).


      -onepix | -twopix
           Specify whether xearth should use one or two pixmaps when
           rendering into an X window. If only one pixmap is used, partial
           redraws may be visible at times in the window (when areas of the
           window are exposed and redrawn during the time xearth is
           rendering the next image). If two pixmaps are used, xearth uses
           them to double-buffer changes such that partial redraws are
           (almost?) never seen. Using only one pixmap has the advantage of
           using quite a bit less memory in the X server; this can be
           important in environments where server-side memory is a fairly
           limited resource. Two pixmaps is the default.


      -mono | -nomono
           If rendering into an X window, enable/disable monochrome mode.
           Monochrome mode is enabled by default on systems with one-bit
           framebuffers (see the "depth of root window" information provided
           by xdpyinfo(1)) and disabled by default otherwise.




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 xearth(1)                           KLJ                           xearth(1)
                                November 1999



      -ncolors num_colors
           If rendering into an X window or a GIF output file, specify the
           number of colors that should be used. (If markers are enabled
           (see -markers, above), the actual number of colors used may be
           one larger than num_colors.) The default value of num_colors is
           64.

           When rendering into an X window, the maximum allowable value for
           num_colors is 1024. In practice, using values of num_colors
           larger than twice the number of distinct shades of red, green, or
           blue supported by your hardware is likely to provide little
           additional benefit, or, in some cases, produce "banding" effects
           in the image. Thus, on systems that can support 256 distinct
           shades of red, green, or blue (eight bits per component), the
           largest practical value of num_colors is around 512. Similarly,
           on systems that support only five or six bits per component
           (e.g., many systems with 16-bit displays), the largest practical
           value of num_colors is probably around 64.

           When rendering into a GIF output file, the maximum allowable
           value for num_colors is 256.


      -font font_name
           If rendering into an X window, use font_name for drawing text
           labels (see -label and -markers, above). By default, xearth uses
           the "variable" font.


      -root | -noroot
           When rendering into an X window, select whether xearth should
           render into the X root window (-root) or create and render into a
           top-level X window (-noroot). By default, xearth renders into the
           X root window.


      -geometry geom
           Cause xearth to create and render into a top-level X window with
           the specified geometry. When this option is used, the -noroot
           option can be elided. Use of the -root overrides the effect of
           -geometry. By default (if -noroot is specified by no geometry is
           provided), xearth uses a geometry of "512x512".


      -title title
           When rendering into a top-level X window, this option can be used
           to specify the window title string that might be displayed by a
           window manager. By default, xearth uses a title of "xearth".






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 xearth(1)                           KLJ                           xearth(1)
                                November 1999



      -iconname iconname
           When rendering into a top-level X window, this option can be used
           to specify the icon name that might be used by a window manager
           for the window. By default, xearth uses an icon name of "xearth".


      -name name
           When rendering into an X window, this option can be used to
           specify the application name under which X resources are
           obtained, rather than the default executable file name. The
           specified name should not contain "." or "*" characters.


      -fork | -nofork
           When rendering into an X window, enable/disable forking. If
           forking is enabled, xearth forks a child process to handle all
           rendering calculations and screen updates (in essence,
           automatically putting itself in the background). Forking is
           disabled by default.


      -once | -noonce
           Disable/enable updates. If updates are enabled and xearth is
           rendering into an X window, xearth updates the displayed image
           periodically (the time between updates can be controlled via the
           -wait option, above). If updates are disabled, xearth only
           renders an image once and then exits. Updates are enabled by
           default.


      -nice priority
           Run the xearth process with priority priority (see nice(1) and
           setpriority(2)). By default, xearth runs at the priority of the
           process that invoked it, usually 0.


      -gif Instead of drawing in an X window, write a GIF file (eight-bit
           color) to standard out.


      -ppm Instead of drawing in an X window, write a PPM file (24-bit
           color) to standard out.


      -display dpyname
           Attempt to connect to the X display named dpyname.


      -version
           Print what version of xearth this is.




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 xearth(1)                           KLJ                           xearth(1)
                                November 1999



 X RESOURCES
      The behavior of xearth can also be controlled using the following X
      resources:


      proj (projection type)
           Specify the projection type xearth should use (see -proj, above).


      pos (position specifier)
           Specify the position from which the Earth should be viewed (see
           -pos, above).


      rot (float)
           Specify the viewing rotation (see -rot, above).


      sunpos (sun position specifier)
           Specify a fixed point on the Earth's surface where the Sun is
           always directly overhead (see -sunpos, above).


      mag (float)
           Specify the magnification of the displayed image (see -mag,
           above).


      size (size specifier)
           Specify the size of the image to be rendered (see -size, above).


      shift (shift specifier)
           Specify that the center of the rendered Earth image should be
           shifted by some amount from the center of the image (see -shift,
           above).


      shade (boolean)
           Enable/disable shading (see -shade, above).


      label (boolean)
           Enable/disable labeling (see -label, above).


      labelpos (geometry)
           Specify where the label should be drawn (see -labelpos, above).






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 xearth(1)                           KLJ                           xearth(1)
                                November 1999



      markers (boolean)
           Enable/disable markers (see -markers, above).


      markerfile (file name)
           Specify a file from which user-defined marker data (locations and
           names) should be read (see -markerfile, above).


      stars (boolean)
           Enable/disable stars (see -stars, above).


      starfreq (float)
           Set the density of the random star pattern (see -starfreq,
           above).


      bigstars (int)
           Set the percentage of stars that are double width (see -bigstars,
           above).


      grid (boolean)
           Enable/disable the display of a longitude/latitude grid on the
           Earth's surface (see -grid, above).


      grid1 (integer)
           Specify the spacing of major grid lines if grid display is
           enabled (see -grid1, above).


      grid2 (integer)
           Specify the spacing of dots along major grid lines if grid
           display is enabled (see -grid2, above).


      day (integer)
           Specify the brightness that should be used to shade the day side
           of the Earth when shading is enabled (see -day, above).


      night (integer)
           Specify the brightness that should be used to shade the night
           side of the Earth when shading is enabled (see -night, above).


      term (integer)
           Specify the shading discontinuity at the terminator (see -term,
           above).



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 xearth(1)                           KLJ                           xearth(1)
                                November 1999



      gamma (float)
           Specify the gamma correction xearth should use when selecting
           colors (see -gamma, above).


      wait (integer)
           Specify the delay between updates when rendering into an X window
           (see -wait, above).


      timewarp (float)
           Specify the apparent rate at which time progresses (see
           -timewarp, above).


      time (integer)
           Specify a particular fixed time that should be used to determine
           the "value" of time-dependent positions (see -time, above).


      twopix (boolean)
           Specify whether xearth should use one or two pixmaps when
           rendering into an X window (see -onepix and -twopix, above).


      mono (boolean)
           Specify whether xearth should use monochrome mode when rendering
           into an X window (see -mono and -nomono, above).


      ncolors (integer)
           Specify the number of colors xearth should use (see -ncolors,
           above). The ncolors resource is only used when rendering into an
           X window -- the number of colors to use when rendering into a GIF
           file can only be specified using the -ncolors command line
           option.


      font (font name)
           Use the named font for drawing text labels (see -font, above).


      root (boolean)
           Specify whether xearth should render into the X root window or a
           top-level X window (see -root, -noroot, and -geometry, above).


      geometry (geometry)
           Specify the geometry of a top-level X window that xearth should
           create and render into (see -geometry, above).




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 xearth(1)                           KLJ                           xearth(1)
                                November 1999



      title (string)
           When rendering into a top-level X window, specify the window
           title that xearth should use (see -title, above).


      iconname (string)
           When rendering into a top-level X window, specify the icon name
           that xearth should use (see -iconname, above).


      fork (boolean)
           When rendering into an X window, enable/disable the automatic
           forking of a child process to handle the updates (see -fork,
           above).


      once (boolean)
           When rendering into an X window, disable/enable updates for the
           displayed image (see -once, above).


      nice (integer)
           Specify the priority at which the xearth process should be run
           (see -nice, above).


 OBTAINING THE XEARTH SOURCE DISTRIBUTION
      The latest-and-greatest version of xearth should always be available
      via a link from the xearth WWW home page (URL
      http://www.cs.colorado.edu/~tuna/xearth/index.html), or, for the web-
      deprived, via anonymous ftp from cag.lcs.mit.edu in /pub/tuna.


 NOTES
      Thanks to Frank Solensky for the "-pos moon" and "-rot galactic"
      stuff.

      The map information used in xearth was derived from the "CIA World
      Data Bank II map database," as taken from some "cbd" files that were
      apparently originally generated by Brian Reid at DEC WRL.

      The Graphics Interchange Format(c) is the Copyright property of
      CompuServe Incorporated. GIF(sm) is a Service Mark property of
      CompuServe Incorporated.

      Thanks to Robert Berger for allowing me to include his nifty gamma
      measurement image and associated text in the xearth source
      distribution.

      Thanks to Jamie Zawinski for suggesting that I look at his
      xscreensaver package for a good example of how to use the resource and



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 xearth(1)                           KLJ                           xearth(1)
                                November 1999



      command line option parts of Xt; his code saved me piles of lossage.

      Thanks to Chris Metcalf for the -bigstars stuff, a pile of general
      source code cleaning, and spell checking everything carefully.

      Thanks to Chris Hayward, Chris Metcalf, Sherman Mui, Dan Rich, and
      Leonard Zubkoff for giving the pre-release of version 1.0 a test
      drive.

      Kudos to Jef Poskanzer for his excellent PBMPLUS toolkit.

      Finally, thanks to everybody that sent encouragement, suggestions, and
      patches. Apologies to the many people whose good ideas didn't make it
      into this release.


 COPYRIGHT
      Copyright (C) 1989, 1990, 1993-1995, 1999 by Kirk Lauritz Johnson

      Portions of the xearth source code, as marked, are:

        Copyright (C) 1989, 1990, 1991 by Jim Frost
        Copyright (C) 1992 by Jamie Zawinski <jwz@lucid.com>

      Permission to use, copy, modify and freely distribute xearth for non-
      commercial and not-for-profit purposes is hereby granted without fee,
      provided that both the above copyright notice and this permission
      notice appear in all copies and in supporting documentation.

      Unisys Corporation holds worldwide patent rights on the Lempel Zev
      Welch (LZW) compression technique employed in the CompuServe GIF image
      file format as well as in other formats. Unisys has made it clear,
      however, that it does not require licensing or fees to be paid for
      freely distributed, non-commercial applications (such as xearth) that
      employ LZW/GIF technology. Those wishing further information about
      licensing the LZW patent should contact Unisys directly at
      (lzw_info@unisys.com) or by writing to

        Unisys Corporation
        Welch Licensing Department
        M/S-C1SW19
        P.O. Box 500
        Blue Bell, PA 19424

      The author makes no representations about the suitability of this
      software for any purpose. It is provided "as is" without express or
      implied warranty.

      THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
      INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
      EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, INDIRECT OR



                                   - 15 -           Formatted:  July 7, 2022






 xearth(1)                           KLJ                           xearth(1)
                                November 1999



      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.


 AUTHOR
        Kirk Johnson <tuna@indra.com>

      Patches, bug reports, and suggestions are welcome, but I can't
      guarantee that I'll get around to doing anything about them in a
      timely fashion.










































                                   - 16 -           Formatted:  July 7, 2022