GP2X Gnu Chess use the GNU Chess version 5.07 for the Artificial Intelligence, and ZX-81’s Graphical User interface.

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, Lukas Geyer, Simon Waters and David A. Wheeler.