GNU Chess(グヌー・チェス)は、人間コンピュータチェスを行うフリーソフトウェアのチェスエンジンである。GNU Chessは研究の基盤を提供することを目標としており、多くの環境で利用されてきた。

GNU Chess
XBoard GNUChess.png
開発元 GNUプロジェクト
初版 1984年(37年前) (1984
6.2.7 / 2020年5月31日(10か月前) (2020-05-31[1]
リポジトリ ウィキデータを編集
対応OS LinuxUNIXMicrosoft WindowsmacOS
サポート状況 開発中
種別 コンピュータチェス
ライセンス GNU GPL v3+

GNU ChessはGNU GPL v3+で公開されているフリーソフトウェアであり、共同開発者によってメンテナンスが行われている。完全なソースコードを提供する最初のコンピュータチェスプログラムの1つである。UNIXベースのシステムで最古のコンピュータチェスプログラムの1つであり、多くのプラットフォーム移植されている。


As of 2 September 2017 GNU Chess 5.60 is rated at 2813 ELO points (when using one CPU) on CCRL's 40-moves-in-40-minutes list. For comparison, the strongest chess engine in the list using one CPU, Strelka 5.5, has a ELO rating of 3108 (the 295 ELO point difference indicates that Strelka 5.5 would beat GNU Chess 5.60 in about 85% of games). On the same list, Fritz 8 is rated at only 2701, and that program in the 2004 Man vs Machine World Team Championship beat grandmasters Sergey Karjakin, Veselin Topalov and reached a draw with Ruslan Ponomariov. The IQ6 test suite (a collection of chess problems from Livshits's book Test Your Chess IQ) indicates that on a single core of an Intel Core 2 Duo CPU GNU Chess performs at the senior master/weak international master strength of 2500+ on the Elo rating system.[要出典]

It is often used in conjunction with a GUI program such as XBoard or glChess, where it is included as the default engine. Initial versions of XBoard's Chess Engine Communication Protocol were based on GNU Chess's command-line interface. Version 6 also supports the Universal Chess Interface (UCI).


The first version of GNU Chess was written by Stuart Cracraft. Having started in 1984 in collaboration with Richard Stallman prior to his founding of the GNU Project, GNU Chess became one of the first parts of GNU.

GNU Chess has been enhanced and expanded by dozens of programmers. Versions from 2 to 4 were written by John Stanback. Version 5 was written by Chua Kong-Sian.

In 2011, GNU Chess transitioned to version 6, which is based on Fabien Letouzey's Fruit 2.1 chess engine. Some GNU Chess enthusiasts have continued to maintain the 5.07 code base.[2] According to CEGT[3] version 5.60 of this code base is stronger than Fruit 2.3, the latest version of that chess engine.


  1. ^ GNU Chess 6.2.7” (2020年5月31日). 2020年6月2日閲覧。
  2. ^ [1]; 5.07 GNU Chess branch
  3. ^ [2]; the CEGT rating list