GNU Chess is command line Chess program running on many differents systems such as UNIX, windows or MacOS. It was started in 1986 by Stuart Cracraft, who is continuing to develop it with other coders such as Chua Kong Sian, Stuart Cracraft, Lukas Geyer, Simon Waters and David A. Wheeler.

PSP Gnu Chess use the GNU Chess version 5.07 for the Artificial Intelligence, and ZX-81 has added a Graphical User interface.