This is the archived version of gnuchess 3.1 along with a chess game analysis program based on gnuchess. The analysis program is called gnuan.exe which uses gnuchess to analyse a whole chess game. It will take a file with the game in algebraic notation, and analyse each move made, tell what it would have done, and give the score it would have given the position after its move. The max depth and max time per move can be set for different levels of analysis. Gnuchess is a public domain chess program from the Free Software Foundation. Gnuchess plays a strong game. It appears to be better than my Novag Super VIP chess computer which was rated between 1950 and 2000 by Computer Chess Reports. Gnuchess was running on an 11 Mhz PC at the time. The human interface is not as good as most chess programs, since the output is ASCII graphics. The gnuchess program is called gnuchess.exe, and it reads gnuchess.boo for its opening book. It comes with source, executables, and makefiles for a variety of compilers. The source code is all in C. It is quite portable code, and should be compilable on other machines with only minor modifications. -Truman