Fruit (software)

Last updated
Fruit
Original author(s) Fabien Letouzey [1]
Initial releaseMarch 17, 2004;19 years ago (2004-03-17) [1] [2]
Final release
2.3.1 / August 2, 2007;15 years ago (2007-08-02) [3]
Type Chess engine
License proprietary freeware (after v2.1)
GNU General Public License (until v2.1)
Website www.fruitchess.com

Fruit is a chess engine developed by Fabien Letouzey. In the SSDF rating list released on November 24, 2006, Fruit version 2.2.1 had a rating of 2842. In the CEGT rating list released on January 24, 2007, Fruit version 2.2.1 had a rating of 2776.

Contents

History

At the World Computer Chess Championship in Reykjavík in 2005, Fruit 2.2 scored 8.5 out of 11, finishing in second place behind Zappa.

Until Version 2.1 (Peach), Fruit was free and open-source software subject to the requirements of the GNU General Public License and as such contributed much to the development in computer chess in recent years. Some people still work on the v2.1 source code and have created variations from the original Fruit.

As of July 23, 2007, Fruit became freeware. Fruit 2.3.1 was one of the top 3 free UCI chess engines.

Technical details of Fruit 2.1

Fruit uses the classical Negascout (principal variation search) algorithm with iterative deepening to traverse the game tree. It also uses the null-move heuristic. The original version used a simplistic evaluation function with a robust search. Later versions have improved evaluation functions. The board representation is distinct — Fruit uses a 16x16 board.

Derivatives

Although in 2007 Fabien Letouzey stopped the development of Fruit with version 2.3.1, the earlier open source 2.1 version provided the basis for many other programs.

Toga II

Toga II is a derivative created by Thomas Gaksch, currently continued by Jerry Donald Watson. It has more chess knowledge, multi-processor support, and perhaps a better search algorithm. [4] It is based on Fruit 2.1 and is free. The strongest version is Toga II 4.0 , released on 29 December 2017 by Jerry Donald Watson. Experimental versions of Toga II running on computer clusters have competed in the World Computer Chess Championship (WCCC). At about 80 ELO above Fruit 2.3.1, Toga II is the strongest Fruit derivative as of March 2014. [5]

In 2008, forks of Toga II started to appear, like Grapefruit and Cyclone.

GambitFruit

GambitFruit is another free derivative of Fruit 2.1, created by Ryan Benitez. It plays a more aggressive style and has more chess knowledge. [4] GambitFruit also incorporates improvements from Toga II. [4] Development of GambitFruit stopped in 2005.

GNU Chess

GNU Chess 6.x is based on Fruit 2.1 and the project is since 2011 under active development.

Fruit Reloaded

Fruit Reloaded by Fabien Letouzey, Daniel Mehrmann and Ryan Benitez is an independent fork of Fruit 2.1 with a number of enhancements. [6]

Rybka controversy

In June 2011, a lengthy investigation by the International Computer Games Association (ICGA) determined Rybka was plagiarized from Fruit and Crafty. [7] The author of Rybka, Vasik Rajlich, refused to address the allegations against Rybka with the ICGA, instead preferring an ex post facto public interview conducted by Nelson Hernandez on July 4, 2011. [8] Rajlich had previously said: I went through the Fruit 2.1 source code forwards and backwards and took many things. [9]

Senpai

On the tenth anniversary of the start of Fruit development in 2014, Fabien Letouzey released a completely new engine, Senpai, under the GPLv3. Senpai makes use of chess engine developments made in the intervening decade. It differs from Fruit in using bitboards and C++11's thread support for SMP. [10]

Related Research Articles

<span class="mw-page-title-main">Computer chess</span> Computer hardware and software capable of playing chess

Computer chess includes both hardware 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 analysis, entertainment and training. Computer chess applications that play at the level of a chess master or higher are available on hardware from supercomputers to smart phones. Standalone chess-playing machines are also available. Stockfish, GNU Chess, Fruit, and other free open source applications are available for various platforms.

<span class="mw-page-title-main">GNU Chess</span> Free software chess engine

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.

ChessBase is a German company that develops and sells chess software, maintains a chess news site, and operates an internet chess server for online chess. Founded in 1986, it maintains and sells large-scale databases containing the moves of recorded chess games. The databases contain data from prior games and provide engine analyses of games, while endgame tablebases offer optimal play in some endgames.

<span class="mw-page-title-main">Chess engine</span> Computer program for chess analysis and game

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.

<span class="mw-page-title-main">HIARCS</span>

HIARCS is a proprietary UCI chess engine developed by Mark Uniacke. Its name is an acronym standing for higher intelligence auto-response chess system. Because Hiarcs is written portable in C, it is available on multiple platforms such as Pocket PC, Palm OS, PDAs, iOS, Microsoft Windows and Mac OS X.

<span class="mw-page-title-main">David Levy (chess player)</span>

David Neil Laurence Levy is an English International Master of chess and a businessman. He is noted for his involvement with computer chess and artificial intelligence, and as the founder of the Computer Olympiads and the Mind Sports Olympiads. He has written more than 40 books on chess and computers.

<i>Fritz</i> (chess) Chess software

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 Horvath's Pandix, and then with Fritz 15, Vasik Rajlich's Rybka.

<span class="mw-page-title-main">Zappa (chess)</span> Chess software

Zappa, Zap!Chess or Zappa Mexico, is a UCI chess engine written by Anthony Cozzie, a graduate student at the University of Illinois at Urbana-Champaign. The program emphasizes sound search and a good use of multiple processors. Earlier versions of Zappa are free and the current version is available at Shredder Computer Chess.

<span class="mw-page-title-main">Rybka</span> Chess engine

Rybka is a computer chess engine designed by International Master Vasik Rajlich. Around 2011, Rybka was one of the top-rated engines on chess engine rating lists and won many computer chess tournaments.

<span class="mw-page-title-main">Vasik Rajlich</span>

Vasik Rajlich is an International Master in chess and the author of Rybka, previously one of the strongest chess playing programs in the world. Rajlich is a dual Czechoslovakian-American citizen by birth; he was born in the United States of America to Czech parents, at that time graduate students, but grew up in Prague. He later spent years in the United States as a student, graduating from MIT.

Events in chess in 1971;

Lawrence Charles Kaufman is an American chess player. In chess, he was awarded the title Grandmaster by FIDE for winning the 2008 World Seniors Championship. Kaufman had been previously awarded the title International Master in 1980.

<span class="mw-page-title-main">Naum (chess)</span>

Naum is a computer chess engine by Canadian programmer Aleksandar Naumov. The last commercial version (4.2) was released in March 2010. The program supports both UCI and Winboard protocols and can therefore be operated under different graphical interfaces. Naum has commercial versions for single and multiple-processor systems, a freeware version for single-processor systems, and a version for Palm OS. The latest version, 4.6, was also freeware.

<span class="mw-page-title-main">Stockfish (chess)</span> Open source chess engine

Stockfish is a free and open-source chess engine, commonly used to calculate the optimal move in various chess scenarios needed for a checkmate. It is available for various desktop and mobile platforms and can be used in chess software through the Universal Chess Interface.

<span class="mw-page-title-main">Houdini (chess)</span>

Houdini is a UCI chess engine developed by Belgian programmer Robert Houdart. It is influenced by open-source engines IPPOLIT/RobboLito, Stockfish, and Crafty. Versions up to 1.5a are available for non-commercial use, while 2.0 and later are commercial only.

Critter is a cross-platform UCI chess engine by Slovakian programmer Richard Vida which is free for non-commercial use. The engine has achieved top five on most official chess engine Elo rating lists.

Strelka is a computer chess engine for Windows, developed by Yuri Osipov. In total five versions of the program have been developed. The current version, 5.5, runs only on a single processor core. Strelka was one of the strongest programs in the world, according to several blitz rating lists and the strongest in Russia at the time.

Top Chess Engine Championship, formerly known as Thoresen Chess Engines Competition, is a computer chess tournament that has been run since 2010. It was organized, directed, and hosted by Martin Thoresen until the end of Season 6; from Season 7 onward it has been organized by Chessdom. It is often regarded as the Unofficial World Computer Chess Championship because of its strong participant line-up and long time-control matches on high-end hardware, giving rise to very high-class chess. The tournament has attracted nearly all the top engines compared to the World Computer Chess Championship.

<span class="mw-page-title-main">Don Dailey</span> American researcher and game programmer

Don Dailey was an American researcher in computer chess and a game programmer. Along with collaborator Larry Kaufman, he was the author of the chess engine Komodo. Dailey started chess programming in the 1980s, and was the author and co-author of multiple commercial as well as academic chess programs. He has been an active poster in computer chess forums and computer Go newsgroups. He was raised as a Jehovah's Witness and served in recent years as an elder in the church of Roanoke.

<span class="mw-page-title-main">Fairy-Max</span>

Fairy-Max is a free and open source chess engine which can play orthodox chess as well as chess variants. Among its features is the ability of users to define and use their own custom variant chess pieces for use in games.

References

  1. 1 2 "Team / History". fruitchess.com. Retrieved 2014-03-17.
  2. Letouzey, Fabien (March 17, 2004). "Fruit 1.0 UCI (with source code) now available". Computer Chess Club Archives. Retrieved March 18, 2014.
  3. Benitez, Ryan (August 2, 2007). "Fruit 2.3.1 released". talkchess.com. Retrieved March 19, 2014.
  4. 1 2 3 Fruit Chess Engine by Fabien Letouzey
  5. "Custom engine selection". CCRL. Retrieved March 18, 2014.
  6. "Fruit Reloaded". 17 March 2014. Retrieved 2014-03-17.
  7. Doggers, Peter. "Rybka disqualified and banned from World Computer Chess Championships". Chess Vibes. Archived from the original on 30 March 2014. Retrieved 29 June 2011.
  8. Hernandez, Nelson. "Another interview with Vasik Rajlich". Archived from the original on 2021-12-21.
  9. "Interview with Vasik Rajlich (Dec 2005)". Archived from the original on 2011-03-05.
  10. "Senpai". 17 March 2014.

Fruit derivatives