GNUChess

GNU Chess - http://users.telenet.be/artificialintelligence/chess/indexGNUChess.html
Contains GNUChess Atari, Chess, Computer chess and source code of these for different platforms

GNU Chess version 4.0b5 for Apple Mac - ftp://ftp.gnu.org/pub/gnu/gnuchess/gnuchessMAC40b5.hqx
Apple Mac port of GNU Chess.

Official site for GNU Chess by the Free Software Foundation (FSF) - http://www.gnu.org/software/chess/chess.html
The official web site for the Free Software Foundation's chess program. This can be used as an engine for Xboard & Winboard.

Tim Mann's Chess Page - GNU Chess - http://www.tim-mann.org/gnuchess.html
Tim Mann's GNU page. A very useful resource for GNU Chess. It includes an extensive FAQ.