GNU Chess is a

free software Free software or libre software is computer software distributed under terms that allow users to run the software for any purpose as well as to study, change, and distribute it and any adapted versions. Free software is a matter of liberty, no ...

chess engine In computer chess, a chess engine is a computer program that analyzes chess or chess variant positions, and generates a move or list of moves that it regards as strongest. A chess engine is usually a back end with a command-line interface wit ...

and

command-line interface A command-line interpreter or command-line processor uses a command-line interface (CLI) to receive commands from a user in the form of lines of text. This provides a means of setting parameters for the environment, invoking executables and pro ...

chessboard A chessboard is a used to play chess. It consists of 64 squares, 8 rows by 8 columns, on which the chess pieces are placed. It is square in shape and uses two colours of squares, one light and one dark, in a chequered pattern. During play, the bo ...

. The goal of

GNU GNU () is an extensive collection of free software (383 packages as of January 2022), which can be used as an operating system or can be used in parts with other operating systems. The use of the completed GNU tools led to the family of operat ...

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 The GNU General Public License (GNU GPL or simply GPL) is a series of widely used free software licenses that guarantee end users the four freedoms to run, study, share, and modify the software. The license was the first copyleft for general u ...

or any later version, and is maintained by collaborating developers. As one of the earliest

computer chess Computer chess includes both hardware (dedicated computers) and software capable of playing chess. Computer chess provides opportunities for players to practice even in the absence of human opponents, and also provides opportunities for analysi ...

programs with full

source code In computing, source code, or simply code, is any collection of code, with or without comments, written using a human-readable programming language, usually as plain text. The source code of a program is specially designed to facilitate the wo ...

available, it is one of the oldest for

Unix Unix (; trademarked as UNIX) is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, and ot ...

-based systems and has since been

ported In software engineering, porting is the process of adapting software for the purpose of achieving some form of execution in a computing environment that is different from the one that a given program (meant for such execution) was originally desi ...

to many other platforms.

Features

As of 2 September 2017 GNU Chess 5.60 is rated at 2813 Elo points (when using one CPU) on

CCRL Computer chess includes both hardware (dedicated computers) and software capable of playing chess. Computer chess provides opportunities for players to practice even in the absence of human opponents, and also provides opportunities for analysi ...

's 40-moves-in-40-minutes list. For comparison, the strongest chess engine in the list using one CPU, Strelka 5.5, has an 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 Fritz is a German chess program originally developed for Chessbase by Frans Morsch based on his Quest program, ported to DOS, and then Windows by Mathias Feist. With version 13, Morsch retired, and his engine was first replaced by Gyula Horvat ...

is rated at only 2701, and that program in the 2004 Man vs Machine World Team Championship beat grandmasters

Sergey Karjakin Sergey Alexandrovich Karjakin, . (born 12 January 1990) is a Russian chess grandmaster (formerly representing Ukraine). A chess prodigy, he previously held the record for the world's youngest ever grandmaster, (until it was eventually taken b ...

Veselin Topalov Veselin Aleksandrov Topalov (pronounced ; bg, Весели́н Александров Топа́лов; born 15 March 1975) is a Bulgarian chess International Grandmaster, grandmaster and former FIDE World Chess Championship, World Chess Champ ...

and reached a draw with

Ruslan Ponomariov Ruslan Olehovych Ponomariov ( uk, Русла́н Оле́гович Пономарьо́в; born 11 October 1983) is a Ukrainian chess grandmaster. He was FIDE World Chess Champion from 2002 to 2004. He won the Ukrainian Chess Championship in ...

. 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 Intel Core is a line of streamlined midrange consumer, workstation and enthusiast computer central processing units (CPUs) marketed by Intel Corporation. These processors displaced the existing mid- to high-end Pentium processors at the time o ...

CPU GNU Chess performs at the senior master/weak international master strength of 2500+ on the

Elo rating system The Elo rating system is a method for calculating the relative skill levels of players in zero-sum games such as chess. It is named after its creator Arpad Elo, a Hungarian-American physics professor. The Elo system was invented as an improved ch ...

. It is often used in conjunction with a

GUI The GUI ( "UI" by itself is still usually pronounced . or ), graphical user interface, is a form of user interface that allows users to interact with electronic devices through graphical icons and audio indicator such as primary notation, inste ...

program such as

XBoard XBoard is a graphical user interface chessboard for chess engines under the X Window System. It is developed and maintained as free software by the GNU project. WinBoard is a port of XBoard to run natively on Microsoft Windows. Overview Original ...

GNOME Chess An open-source video game, or simply an open-source game, is a video game whose source code is open-source. They are often freely distributable and sometimes cross-platform compatible. Definition and differentiation Not all open-source games ...

, where it is included as the default engine. Initial versions of XBoard's

Chess Engine Communication Protocol In computer chess, a chess engine is a computer program that analyzes chess or chess variant positions, and generates a move or list of moves that it regards as strongest. A chess engine is usually a back end with a command-line interface with n ...

were based on GNU Chess's

. Version 6 also supports the

Universal Chess Interface The Universal Chess Interface (UCI) is an open communication protocol that enables chess engines to communicate with user interfaces. History In November 2000, the UCI protocol was released. Designed by Rudolf Huber and Stefan Meyer-Kahlen, the au ...

(UCI). Since version 6.1 GNU chess supports a graphical mode for terminal emulators. Gnuchess-terminal

History

The first version of GNU Chess was written by Stuart Cracraft. Having started in 1984 in collaboration with

Richard Stallman Richard Matthew Stallman (; born March 16, 1953), also known by his initials, rms, is an American free software movement activist and programmer. He campaigns for software to be distributed in such a manner that its users have the freedom to ...

prior to his founding of the

GNU Project The GNU Project () is a free software, mass collaboration project announced by Richard Stallman on September 27, 1983. Its goal is to give computer users freedom and control in their use of their computers and computing devices by collaborati ...

, GNU Chess became one of the first parts of GNU. GNU Chess has been enhanced and expanded since. Versions from 2 to 4 were written by John Stanback. Version 5 of GNU Chess was based on the Cobalt chess engine 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. According to

CEGT Chess Engines Grand Tournament, also known as CEGT, is an organization that tests computer chess software by playing chess engines against one another and publishing a ratings table. CEGT routinely tests chess engines in various time controls suc ...

version 5.60 of this code base is stronger than Fruit 2.3, the latest version of that chess engine.

Notes

References

External links

* {{DEFAULTSORT:Gnu Chess 1984 software Chess engines DOS games Free chess software Free educational software

Chess Chess is a board game for two players, called White and Black, each controlling an army of chess pieces in their color, with the objective to checkmate the opponent's king. It is sometimes called international chess or Western chess to disti ...

GP2X games Linux games Unix games Video games developed in the United States Windows games

Features

History

See also

Notes

References

External links