Welcome to GNU MDK. GNU MDK is part of the GNU project . MDK stands for MIX Development Kit, and provides tools for developing and executing, in a MIX virtual machine, MIXAL programs. The MIX is Donald Knuth's mythical computer, described in the first volume of The Art of Computer Programming, which is programmed using MIXAL, the MIX assembly language. MDK includes a MIXAL assembler (mixasm) and a MIX virtual machine (mixvm) with a command line interface. In addition, a GTK+ GUI to mixvm, called gmixvm, is provided; and, in case you are an Emacs guy, you can try misc/mixvm.el, which allows running mixvm inside an Emacs GUD buffer. Using these interfaces, you can debug your MIXAL programs at source code level, and read/modify the contents of all the components of the MIX computer (including block devices, which are simulated using the file system). Project homepage: http://www.gnu.org/software/mdk/mdk.html GNU MDK is free software. Please see the file COPYING for details. For documentation, please see the files in the doc subdirectory. For building and installation instructions please see the INSTALL file. For sample MIXAL programs, please see the samples subdirectory. For translations (MDK uses GNU's gettext), please see the po subdirectory. --  To learn more about GNU, the FSF and its goals, please visit http://www.gnu.org.  New translations are welcome. If you'd like to contribute one, please contact the author, email@example.com.