GNU Chess

GNU Chess

GNU Chess 6.0.0 running with the XBoard front end, v. 4.1.5.
Developer(s)	GNU Project
Initial release	1984; 41 years ago (1984)
Stable release	6.2.11[1]  / 19 April 2025
Repository	git.savannah.gnu.org/cgit/chess.git
Operating system	Linux, Unix, macOS, Windows
Type	Computer chess
License	2010[a]: GPL-3.0-or-later 1992[b]: GPL-2.0-or-later 1986: Chess-GPL[c][2][3]
Website	www.gnu.org/software/chess/

This article is part of the series on
Chess programming
Board representations 0x88 Bitboards
Evaluation functions Deep neural networks (Transformers) Attention Efficiently updatable neural networks Handcrafted evaluation functions Piece-square tables Reinforcement learning Stochastic gradient descent Supervised learning Texel tuning Unsupervised learning
Graph and tree search algorithms Minimax Alpha-beta pruning Principal variation search Quiescence search Monte Carlo tree search
Chess computers Belle ChessMachine ChipTest Cray Blitz Deep Blue Deep Thought HiTech Hydra Mephisto Saitek
Chess engines AlphaZero Chess Tiger Crafty CuckooChess Deep Fritz Dragon by Komodo Chess Fairy-Max Fritz Fruit GNU Chess HIARCS Houdini Ikarus Junior KnightCap Komodo Leela Chess Zero MChess Pro Mittens MuZero Naum REBEL Rybka Shredder Sjeng SmarThink Stockfish Torch Turochamp Zappa
v t e

GNU Chess is a free software chess engine and command-line interface chessboard. The goal of GNU Chess is to serve as a basis for research, and as such it has been used in numerous contexts.

GNU Chess is free software, licensed under the terms of the GNU General Public License version 3 or any later version, and is maintained by collaborating developers. As one of the earliest computer chess programs with full source code available, it is one of the oldest for Unix-based systems and has since been ported to many other platforms.

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