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Created page with "'''Home * Engines * Fruit''' border|right|thumb| [[Arts#Bak|Samuel Bak - After the Perquisition, 1994 <ref>After t..."
'''[[Main Page|Home]] * [[Engines]] * Fruit'''
[[FILE:BakAfterThePerquisition1994.jpg|border|right|thumb| [[Arts#Bak|Samuel Bak]] - After the Perquisition, 1994
<ref>After the Perquisition, 1994 in [https://static1.squarespace.com/static/594044bd3a041171e0426683/t/5a12fdbec83025eab3732a02/1511194070554/Fruit+of+Knowledge1995.pdf Samual Bak - The Fruit of Knowledge] (pdf) from the [https://www.puckergallery.com/artists/#/samuel-bak/ Pucker Gallery - Samuel Bak]</ref> ]]
'''Fruit''',<br/>
until Version 2.1 [[Open Source Engines|open source]], is a groundbreaking [[UCI]] compatible chess engine developed by primary author [[Fabien Letouzey]]. It made its first appearance to the public in March 2004, when Fruit was a basic program with a very simple [[Evaluation |evaluation]] and basic [[Search|search]]. However, since then it made progress adding about 100 Elo to each new release (1.5, 2.0, 2.1 and Fruit 2.2) <ref>[http://www.fruitchess.com/about.htm Fruit - pure playing strength - Team / History]</ref>.
=Revolution=
The release of Fruit until version '''2.1''' under the [[Free Software Foundation#GPL|GNU General Public License]] was a "revolution" in computer chess in 2005 - an open source engine was "suddenly" competitive with the long time leading programs [[Shredder]] and [[Junior]], as demonstrated at the [[WCCC 2005]], where Fruit became runner up behind [[Zappa]]. After the strong [[Massy 2005]] over the board debut, and the great success of Reykjavik, where Fabien Letouzey met his professional colleagues, he decided to close the source <ref>[https://www.stmintz.com/ccc/index.php?id=444731 Re: Fruit Reykjavic] by [[Fabien Letouzey]], [[CCC]], August 24, 2005</ref> and to go commercial <ref>[https://www.stmintz.com/ccc/index.php?id=449961 Fruit commercial] by [[Fabien Letouzey]], [[CCC]], September 16, 2005</ref> - while Fruit derivatives have already appeared based on the source code of Fruit 2.1, most notably [[Toga]] by [[Thomas Gaksch]], and [[Gambit Fruit]] by [[Ryan Benitez]], who in late 2005 joint forces with Fabian for the commercial endeavor. Fabien finished his commercial computer chess career so far in 2007 <ref>[http://www.fruitchess.com/ Fruit - pure playing strength]</ref>. Fruit '''2.3+''' is non [[Free Software Foundation#GPL|GPL]] with full rights given to [[Ryan Benitez]] who continued the Fruit development porting it to [[Bitboards|bitboards]] <ref>[http://www.talkchess.com/forum/viewtopic.php?t=19164&start=1 Re: How many "official" Toga projects there is now] by [[Ryan Benitez]], [[CCC]], January 24, 2008</ref>, while Fruit 2.1 is now owned by the [[Free Software Foundation]] <ref>[http://www.talkchess.com/forum/viewtopic.php?topic_view=threads&p=260688&t=27385 Re: When will come a new Toga Engine?] by [[Ryan Benitez]] from [[CCC]], April 10, 2009</ref>, released as [[GNU Chess|GNU Chess 6]] <ref>[http://www.talkchess.com/forum/viewtopic.php?t=37789 GNU Chess 6 (= Fruit)] by [[Harm Geert Muller]], [[CCC]], January 25, 2011</ref>.
=Tournament Play=
Fruit had its strong debut at [[CCT7]], February 2005, and over the board at [[Massy 2005]] in June 2005, with the then surprising shared second place, tied with [[Chess Wizard]] behind [[AnMon]]. After the mentioned breakthrough at the [[WCCC 2005]] in Reykjavík, Fruit played the [[DOCCC 2005]], operated by new book author [[Jeroen Noomen]], who short later left the team for [[Rybka]], the [[IPCCC 2005 b]], [[CCT8]] and the [[DOCCC 2006]]. Fruit continued to play [[CCT Tournaments]] from [[CCT10]] in 2008.
=Photos & Games=
[[FILE:ShredderFruit2005.jpg|none|border|text-bottom|640px]]
[[Stefan Meyer-Kahlen]] and [[Fabien Letouzey]], [[Shredder]] - Fruit, [[WCCC 2005]] <ref>Photo by [[Gerd Isenberg]]</ref>
<pre>
[Event "WCCC 2005"]
[Site "Reykjavík, Iceland"]
[Date "2005.08.16"]
[Round "5"]
[White "Shredder"]
[Black "Fruit"]
[Result "0-1"]
1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 Nc6 5.Nc3 a6 6.Be2 d6 7.Be3 Nf6 8.f4 Be7 9.O-O Qc7
10.Qe1 O-O 11.Kh1 Nxd4 12.Bxd4 b5 13.Qg3 Bb7 14.a3 Bc6 15.Bd3 Rfd8 16.Rae1 Qb7 17.Bxf6
Bxf6 18.e5 Be7 19.Ne4 dxe5 20.fxe5 Rd5 21.Re2 Rf8 22.Nf6+ Bxf6 23.Rxf6 Rd4 24.Rh6 g6
25.Rh4 Rxh4 26.Qxh4 Qb6 27.Qf4 Rd8 28.Rf2 Rd7 29.c3 Qc7 30.Qe3 Qd8 31.Bf1 Rd1 32.Kg1 Qd5
33.Re2 a5 34.Qf2 b4 35.axb4 axb4 36.cxb4 h6 37.Re1 Rxe1 38.Qxe1 Qd4+ 39.Qf2 Qxb4 40.h3
Be4 41.Kh2 Bd5 42.Bd3 Qb7 43.Qf6 Qb6 44.Qh4 Qb8 45.Qf6 Qb7 46.Bb1 Qd7 47.Qh4 Qc7 48.Qf4
Ba8 49.b4 Qb7 50.Qd2 Kg7 51.Qb2 Qb5 52.Kg1 h5 53.Ba2 Qd3 54.Qf2 Kg8 55.Kh2 Be4 56.Qb2 h4
57.b5 g5 58.Qf2 Qc3 59.b6 Kf8 60.Kg1 Qa1+ 61.Kh2 Qxe5+ 62.Kg1 Qa1+ 63.Kh2 Qc3 64.Kg1 Ke7
65.Kh2 f5 66.Kg1 Kd7 67.Kh2 Kc6 68.Qe2 Kxb6 69.Qf2+ Kc6 70.Qe2 Kd6 71.Bc4 Qe5+ 72.Kg1 Qd4+
73.Kh2 g4 74.hxg4 fxg4 75.Qxg4 Qxc4 76.Qxh4 Qe2 77.Qd8+ Kc6 78.Qc8+ Kb5 79.Qb8+ Kc4 80.Qc7+
Kd3 81.Qd6+ Bd5 82.Qa6+ Kd2 83.Qa5+ Kc2 84.Qa4+ Bb3 85.Qd4 e5 86.Qa7 e4 87.Qc5+ Bc4 88.Qa3
Qd3 89.Qa5 e3 90.Qa4+ Qb3 91.Qe8 e2 92.Qe4+ Kb2 93.Qh4 Qc3 94.Qf2 0-1
</pre>
=Innovations=
Fruit was and still is one of the most influential didactic open source programs. It uses a 16x12 [[Vector Attacks|Vector attack]] [[Board Representation|board representation]], since Version 1.5 a 16x16 board to have a symmetric treatment of files and ranks <ref>[http://www.open-aurec.com/wbforum/viewtopic.php?f=4&t=2407&p=11195#p11109 Re: Fruit's Board Representation?] by [[Fabien Letouzey]], [[Computer Chess Forums|Winboard Forum]], April 28, 2005</ref> . Its structure and [[C]] source code was very clean and apparently bug-free due to runtime checking a lot of preconditions using [[Debugging|debug asserts]]. While [[Late Move Reductions|late move reductions]] (LMR) might be used in other programs before, Fabien's [[History Heuristic|history]] based implementation in conjunction with [[History Leaf Pruning|history leaf pruning]] made LMR very popular. Another Fruit innovation, despite not absolutely new and already a known issue, and related to what is mentioned in [[Evaluation Philosophy|evaluation philosophy]], was [[Tapered Eval|tapered evaluation]] to avoid [[Evaluation Discontinuity|discontinuity]] <ref>[https://www.stmintz.com/ccc/index.php?id=470647 Secrets of Rybka and Fruit from my point of view] by [[Sergei Markoff]], [[CCC]], December 15, 2005</ref> .
* [[Evaluation Philosophy]]
* [[History Heuristic]]
* [[History Leaf Pruning]]
* [[Late Move Reductions]]
* [[Null Move Pruning]]
* [[Tapered Eval]]
=Fruit Team=
Beside Fabien Letouzey as primary author and [[Opening Book Authors|opening book author]] [[Marc Lacrosse]], [[Ryan Benitez]] joined the Fruit-Team in December 2005. Before he developed [[Gambit Fruit]] with some interesting changes on the basis of the last open-source-version 2.1. [[Joachim Rang]] was the main tester of Fruit since its first public appearance, tuned parameters, and tested evaluation and search features <ref>[http://www.fruitchess.com/about.htm Fruit - pure playing strength - Team / History]</ref> .
* [[Fabien Letouzey]]
* [[Marc Lacrosse]] <ref>[https://www.stmintz.com/ccc/index.php?id=462330 To Fruit's author Fabien Letouzey and commercial manager Joachim Rang] by [[Marc Lacrosse]], [[CCC]], November 17, 2005</ref>
* [[Ryan Benitez]]
* [[Joachim Rang]]
<span id="Fruit64"></span>
=Fruit 64=
[[Ryan Benitez]] continued the development on the non public Fruit in 2007 <ref>[http://www.talkchess.com/forum/viewtopic.php?t=17559&start=1 Re: Question to co-Author of Fruit and Chess64, Ryan Benitez] by [[Ryan Benitez]], [[CCC]], November 03, 2007</ref>. He converted the board representation from [[Vector Attacks|vector attacks]] to [[Bitboards|bitboards]], and naturally, Fruit has become a new [[Evaluation|evaluation]] to go along with that <ref>[http://www.talkchess.com/forum/viewtopic.php?topic_view=threads&p=256307&t=26965 Re: Fruit vs. Toga poll] by [[Ryan Benitez]], [[CCC]], March 19, 2009</ref>. Fruit by Fabien Letouzey and Ryan Benitez played the [[CCT10]], the [[CCT11]], where it became shared winner along with [[Bright]] after the later [[Rybka]] disqualification <ref>[https://cctchess.com/previous-events/cct-11/results/ CCT11: Bright by Allard Siemelink and Fruit by Fabien Letouzey are Co-Champions]</ref>, and the [[CCT13]] in 2011.
=Influence=
Many programmers took a lot of ideas and implementation details from Fruit, as noted by [[Vasik Rajlich]] <ref>[http://www.top-5000.nl/int/rybka.htm Interview with Vasik Rajlich] by [[Christopher Conkie]], [[Michael Diosi]], [[Frank Quisinsky]] & [[Alexander Schmidt]], December 20, 2005, hosted by [[Ed Schroder|Ed Schröder]]</ref> :
[[Alexander Schmidt]]:
The increase in playing strength of the latest chess engines is unbelieveable. We have since some time with Fruit 2.1 by Fabien Letouzey a very strong open source engine. Do you see a relation between the published sources of such a strong engine and the increase of strength in computer chess in general? How much influence do the ideas of Fruit have on the future of computerchess?
[[Vasik Rajlich]]:
Yes, the publication of Fruit 2.1 was huge. Look at how many engines took a massive jump in its wake: [[Rybka]], [[Hiarcs]], [[Fritz]], [[Zappa]], [[Spike]], [[List (program)|List]], and so on. I went through the Fruit 2.1 source code forwards and backwards and took many things.
<span id="reloaded"></span>
=Fruit Reloaded=
In March 2014, ten years after the initial Fruit 1.0 release, [[Daniel Mehrmann]] initiated a "let's update Fruit" called [[Fruit Reloaded]] <ref>[http://www.talkchess.com/forum/viewtopic.php?t=51638 Fruit 1.0 anniversary] by [[Fabien Letouzey]], [[CCC]], March 17, 2014</ref>. With some help from [[Ryan Benitez]], the aim is to add [[Parallel Search|SMP]] to Fruit and upgrade search and [[Evaluation|evaluation]] with modern techniques <ref>[https://github.com/Akusari/Fruit-reloaded-public Akusari/Fruit-reloaded-public · GitHub]</ref> <ref>[http://www.chessprogramming.net/fruit-reloaded/ Fruit Reloaded - Computer Chess Programming] hosted by [[Steve Maughan]]</ref>. Simultaneously, Fabien Letouzey waved goodbye to Fruit and published his new [[Open Source Engines|open source engine]] [[Senpai]], also with [[Ryan Benitez]] and [[Joachim Rang]] involved <ref>[http://www.talkchess.com/forum/viewtopic.php?t=51637 Senpai 1.0 (new engine)] by [[Fabien Letouzey]], [[CCC]], March 17, 2014</ref>.
=Derivatives=
* [[Cluster Toga]]
* [[Cyclone]]
* [[Fruit Reloaded]]
* [[Gambit Fruit]]
* [[GNU Chess|GNU Chess 6]]
* [[GridChess]]
* [[Lion]]
* [[Patriot]] 2.0
* [[Rybka]]
* [[Strelka]]
* [[Toga]]
=See also=
* [[Chess-64]]
* [[Cipollino]]
* [[Various Classifications#Food|Food]]
* [[ICGA Investigations]]
: [[Rybka Controversy]]
* [[Senpai]]
* [[WCCC 2005]]
=Publications=
* [[Mark Watkins]] ('''2011'''). ''A comparison of Rybka 1.0 Beta and Fruit 2.1'', [http://www.open-chess.org/download/file.php?id=272 pdf, February 12, 2011 Version] <ref>[http://www.open-chess.org/viewtopic.php?f=5&t=1104 Feb 12 version: Rybka 1.0 Beta / Fruit 2.1 document] by [[Mark Watkins]], [[Computer Chess Forums|OpenChess General Forum]], February 12, 2011</ref>
* [[Mark Watkins]] ('''2011'''). ''A comparison of Rybka 1.0 Beta and Fruit 2.1'', [http://www.open-chess.org/download/file.php?id=304 pdf, February 24, 2011 Version]
* [[Mark Watkins]] ('''2011'''). ''A comparison of Rybka 1.0 Beta and Fruit 2.1'', [http://www.open-chess.org/download/file.php?id=332 pdf, March 11, 2011 Version] » [[Rybka]]
* [[Jaap van den Herik]], [[Krzysztof Siewicz]] ('''2011'''). ''Open Source has a Price''. [[ICGA Journal#34_2|ICGA Journal, Vol. 34, No. 2]]
=Forum Posts=
==2004==
* [https://www.stmintz.com/ccc/index.php?id=353818 Fruit Results], by Afzal Siddique, [[CCC]], March 10, 2004
* [https://www.stmintz.com/ccc/index.php?id=353927 Fruit: first observations. Not a coconut yet, a budding pomegranate?] by [[Đorđe Vidanović]], [[CCC]], March 10, 2004
* [https://www.stmintz.com/ccc/index.php?id=354012 Fruit - Question for Fabien] by [[Dan Honeycutt]], [[CCC]], March 11, 2004 » [[Node Types]], [[Transposition Table]], [[Principal variation]], [[Principal Variation Search]]
* [https://www.stmintz.com/ccc/index.php?id=354194 What makes Fruit so strong?] by [[Steve Maughan]], March 12, 2004
* [https://www.stmintz.com/ccc/index.php?id=354644 Fruit, trying to answer various missed posts] by [[Fabien Letouzey]], [[CCC]], March 15, 2004
* [https://www.stmintz.com/ccc/index.php?id=355103 Fruit 1.0 UCI (with source code) now available] by [[Fabien Letouzey]], [[CCC]], March 17, 2004
* [https://www.stmintz.com/ccc/index.php?id=356705 Fruit 1.0 64-bit] by [[Slater Wold]], [[CCC]], March 26, 2004
* [https://www.stmintz.com/ccc/index.php?id=368930 Fruit 1.5 UCI available (Windows/Linux/MacOS + source code)!] by [[Fabien Letouzey]], [[CCC]], June 04, 2004
* [https://www.stmintz.com/ccc/index.php?id=369055 Fruit 1.5 released!] by [[Joachim Rang]], [[CCC]], June 05, 2004
* [https://www.stmintz.com/ccc/index.php?id=371315 Fruit 1.5 Hash Hit Percentage] by [[Robert Allgeuer]], [[CCC]], June 19, 2004
* [https://www.stmintz.com/ccc/index.php?id=378541 null move question(Fruit)] by [[Jan Kaan|Jan K.]], [[CCC]], July 22, 2004
* [https://www.stmintz.com/ccc/index.php?id=402402 Fruit 2.0 released!] by [[Joachim Rang]], [[CCC]], December 24, 2004
==2005==
* [https://www.stmintz.com/ccc/index.php?id=404043 Fruit2 = Ruffian with source code!] by [[Jouni Uski]], [[CCC]], January 04, 2005
* [https://www.stmintz.com/ccc/index.php?id=405159 Fruit 2 and endgame play] by [[Jouni Uski]], [[CCC]], January 12, 2005
* [http://www.open-aurec.com/wbforum/viewtopic.php?f=4&t=2407&p=11195 Fruit's Board Representation?] by [[Steve Maughan]], [[Computer Chess Forums|Winboard Programming Forum]], April 27, 2005
* [https://www.stmintz.com/ccc/index.php?id=426309 why is Patriot 2.0 beta ?] by [[Matthias Gemuh]], [[CCC]], May 16, 2005 » [[Patriot]]
: [https://www.stmintz.com/ccc/index.php?id=426427 Re: why is Patriot 2.0 beta ?] by [[Fabien Letouzey]], [[CCC]], May 17, 2005
* [https://www.stmintz.com/ccc/index.php?id=431280 Re: What makes Fruit and Fruit-Toga so strong?] by [[Fabien Letouzey]], [[CCC]], June 15, 2005
* [http://www.open-aurec.com/wbforum/viewtopic.php?f=4&t=2869&p=13538 understanding fruit] by [[Uri Blass]], [[Computer Chess Forums|Winboard Programming Forum]], June 18, 2005
* [https://www.stmintz.com/ccc/index.php?id=432238 Temptation for Fabien: going commercial] by [[Matthias Gemuh]], [[CCC]], June 20, 2005
* [https://www.stmintz.com/ccc/index.php?id=438699 Fruit on Pocket PC] by [[Alain Zanchetta]], [[CCC]], July 27, 2005 » [[CEBoard]], [[Pocket PC]]
* [https://www.stmintz.com/ccc/index.php?id=440956 Re: Some details] by [[Joachim Rang]], [[CCC]], August 09, 2005
* [https://www.stmintz.com/ccc/index.php?id=444731 Re: Fruit Reykjavic] by [[Fabien Letouzey]], [[CCC]], August 24, 2005
* [https://www.stmintz.com/ccc/index.php?id=449961 Fruit commercial] by [[Fabien Letouzey]], [[CCC]], September 16, 2005
* [https://www.stmintz.com/ccc/index.php?id=460591 Re: Fact is also that Fruit went commercial] by [[Eduard Nemeth]], [[CCC]], November 09, 2005
* [https://www.stmintz.com/ccc/index.php?id=461801 Re: Gambit Fruit ?] by [[Ryan Benitez|Ryan B.]], [[CCC]], November 15, 2005
* [https://www.stmintz.com/ccc/index.php?id=461958 Has anyone tested Gambit Fruit with Rebel Reductions on?] by [[Ryan Benitez|Ryan B.]], [[CCC]], November 15, 2005 » [[Reductions]], [[Rebel]] <ref>[http://www.top-5000.nl/authors/rebel/chess840.htm#REDUCTIONS Programmer Corner - How Rebel Plays Chess - Reductions] by [[Ed Schroder|Ed Schröder]], [http://members.home.nl/matador/Inside%20Rebel.pdf pdf reprint]</ref>
* [https://www.stmintz.com/ccc/index.php?id=462330 To Fruit's author Fabien Letouzey and commercial manager Joachim Rang] by [[Marc Lacrosse]], [[CCC]], November 17, 2005
* [https://www.stmintz.com/ccc/index.php?id=462901 Gambit Fruit Beta 3 available] by [[Ryan Benitez|Ryan B.]], [[CCC]], November 19, 2005
* [https://www.stmintz.com/ccc/index.php?id=464128 A. STEEN vs. FRUIT 2.2.1 {Posted at request of Graham Banks & M. Monge}] by A. Steen, [[CCC]], November 24, 2005
* [https://www.stmintz.com/ccc/index.php?id=470607 Unmasking the Secrets of Rybka and Fruit] by [[Stuart Cracraft]], [[CCC]], December 15, 2005
* [https://www.stmintz.com/ccc/index.php?id=470647 Secrets of Rybka and Fruit from my point of view] by [[Sergei Markoff]], [[CCC]], December 15, 2005
==2006==
* [https://www.stmintz.com/ccc/index.php?id=478190 SSDF(Fruit 2.2.1 - Ruffian 1.0.1)A1200, 2½-2½, ended 26-14] by [[Tony Hedlund]], [[CCC]], January 09, 2006 » [[SSDF]], [[Ruffian]]
* [https://www.stmintz.com/ccc/index.php?id=478224 not correct information in fruit's site] by [[Uri Blass]], [[CCC]], January 09, 2006
* [https://www.stmintz.com/ccc/index.php?id=479189 congratulations to gambit-fruit!] by [[Thorsten Czub]], [[CCC]], January 13, 2006 » [[Gambit Fruit]]
* [https://www.stmintz.com/ccc/index.php?id=479366 Rybka and Fruit on Chessbase] by [[Walter Faxon]], [[CCC]], January 14, 2006 » [[Rybka]], [[ChessBase]]
* [https://www.stmintz.com/ccc/index.php?id=479410 SSDF(Fritz 9 - Fruit 2.2.1)A1200, 1.5-1.5, ended 21-19] by [[Tony Hedlund]], [[CCC]], January 14, 2006 » [[SSDF]], [[Fritz]]
* [https://www.stmintz.com/ccc/index.php?id=481382 SSDF Fruit 2.2.1 A1200 - Junior 7.0 A1200 Ended: 38.5-8.5] by [[Paul Petersson]], [[CCC]], January 22, 2006 » [[SSDF]], [[Junior]]
* [https://www.stmintz.com/ccc/index.php?id=483065 SSDF(Hiarcs 10 - Fruit 2.2.1)A1200, 1-2, ended 19-21] by [[Tony Hedlund]], [[CCC]], January 29, 2006 » [[SSDF]], [[Hiarcs]]
* [https://www.stmintz.com/ccc/index.php?id=489916 What are the moves of the loss of fruit against hiarcs?] by [[Uri Blass]], [[CCC]], February 26, 2006 » [[CCT8]]
* [https://www.stmintz.com/ccc/index.php?id=491661 Fruit depth] by [[Stuart Cracraft]], [[CCC]], March 06, 2006 » [[Depth]], [[Branching Factor]]
* [https://www.stmintz.com/ccc/index.php?id=492114 Toga II 1.2 Beta2a based on Fruit released] by [[Thomas Gaksch]], [[CCC]], March 08, 2006
==2007==
* [http://www.talkchess.com/forum/viewtopic.php?t=13446 SSDF(Hiarcs 11.1 - Fruit 2.2.1)A1200, 12-7, ended 24-24] by [[Tony Hedlund]], April 28, 2007 » [[SSDF]], [[Hiarcs]]
* [http://www.talkchess.com/forum/viewtopic.php?t=14661 SSDF(Zap!Chess Zanzibar-Fruit 2.2.1)A1200 3½-2½ ende 22½-17½] by [[Tony Hedlund]], June 24, 2007 » [[SSDF]], [[Zappa]]
* [http://www.talkchess.com/forum/viewtopic.php?t=15076 Fruit, Rybka, Strelka final conclusion! (I hope)] by [[Michael Sherwin]], [[CCC]], July 13, 2007 » [[Rybka]], [[Strelka]]
* [http://www.talkchess.com/forum/viewtopic.php?t=15094 What is Fruit? Fabien explains!] by [[Michael Sherwin]], [[CCC]], July 14, 2007
* [http://www.talkchess.com/forum/viewtopic.php?t=15219 Fruit and History Reductions] by [[Ed Schroder|Ed Schröder]], [[CCC]], July 19, 2007 » [[Late Move Reductions]]
* [http://www.talkchess.com/forum/viewtopic.php?t=15249 Fruit availability - 2 questions] by Kaj Soderberg, [[CCC]], July 20, 2007
: [http://www.talkchess.com/forum/viewtopic.php?t=15249&start=6 Re: Fruit availability - 2 questions] by [[Ryan Benitez]], [[CCC]], July 21, 2007
* [http://www.talkchess.com/forum/viewtopic.php?t=15310 Fruit is already a free chess engine...] by [[Dr. Wael Deeb|Dr.Wael Deeb]], [[CCC]], July 23, 2007
* [http://www.talkchess.com/forum/viewtopic.php?t=15328 Fruit 2.2.1 : 2687] by [[Patrick Buchmann]], [[CCC]], July 24, 2007
* [http://www.talkchess.com/forum/viewtopic.php?t=15358 Fruit 2.3 released] by [[Ryan Benitez]], [[CCC]], July 26, 2007
* [http://www.talkchess.com/forum/viewtopic.php?t=15488 Fruit 2.3 : 2689] by [[Patrick Buchmann]], [[CCC]], July 31, 2007
* [http://www.talkchess.com/forum/viewtopic.php?t=15533 Fruit 2.3.1 released] by [[Ryan Benitez]], [[CCC]], August 02, 2007
* [http://www.talkchess.com/forum/viewtopic.php?t=15626 Fruit 2.3.1 : 2673] by [[Patrick Buchmann]], [[CCC]], August 06, 2007
* [http://www.talkchess.com/forum/viewtopic.php?t=15981 Is Toga still weaker than Fruit?] by [[Jouni Uski]], [[CCC]], August 23, 2007
* [http://www.talkchess.com/forum/viewtopic.php?t=17260 Fruit2.3.1 stalemate bug] by [[Uri Blass]], [[CCC]], October 21, 2007
* [http://www.talkchess.com/forum/viewtopic.php?t=17559 Question to co-Author of Fruit and Chess64, Ryan Benitez] by [[Swaminathan Natarajan|Swaminathan]], [[CCC]], November 03, 2007
* [http://www.talkchess.com/forum/viewtopic.php?t=18391 Fruit SMP 2.3.4e Beta] by Daniel Charles, [[CCC]], December 15, 2007
==2008==
* [http://www.talkchess.com/forum/viewtopic.php?t=19164&start=1 Re: How many "official" Toga projects there is now] by [[Ryan Benitez]], [[CCC]], January 24, 2008
* [http://www.talkchess.com/forum/viewtopic.php?t=20106 Has Fruit finaly surpassed Rybka!?] by [[Dr. Wael Deeb|Dr.Wael Deeb]], [[CCC]], March 11, 2008
* [http://www.talkchess.com/forum/viewtopic.php?t=22359 Fruit 2.1 pruning] by [[Chua Kong Sian|kongsian]], [[CCC]], July 15, 2008 » [[Pruning]]
* [http://www.talkchess.com/forum/viewtopic.php?t=23095 Fruit 2.1 vs Strelka 2.0] by [[Norman Schmidt]], [[CCC]], August 18, 2008
* [http://www.talkchess.com/forum/viewtopic.php?t=23172 counting similiarities between strelka2.0 and fruit2.1] by [[Uri Blass]], [[CCC]], August 22, 2008
* [http://www.talkchess.com/forum/viewtopic.php?t=24504 Strelka = Rybka 1.0 =Fruit 2.1 = Toga?? Oh how disappointing] by [[Oliver Brausch]], [[CCC]], October 21, 2008 » [[Strelka]], [[Rybka]], [[Toga]]
* [http://www.computerchess.info/tdbb/phpBB3/viewtopic.php?f=9&t=225&start=0&st=0&sk=t&sd=a Chess engine oldies upgrades] by [[Denis Mendoza|Denis P. Mendoza]], [[Computer Chess Forums|Toga Developers Discussion Board]], December 30, 2008 » [[Gambit Fruit]]
==2009==
* [http://www.talkchess.com/forum/viewtopic.php?t=26282 posix source for GambitFruit4bxSE ?] by Martin Helmer, [[CCC]], January 28, 2009
* [http://www.talkchess.com/forum/viewtopic.php?t=26965 Fruit vs. Toga poll] by [[Miguel A. Ballicora]], [[CCC]], March 11, 2009
: [http://www.talkchess.com/forum/viewtopic.php?topic_view=threads&p=256307&t=26965 Re: Fruit vs. Toga poll] by [[Ryan Benitez]], [[CCC]], March 19, 2009
* [http://www.talkchess.com/forum/viewtopic.php?t=27186 Error in Fruit 2.1 source?] by [[Ernest Bonnem]], [[CCC]], March 25, 2009
* [http://www.talkchess.com/forum/viewtopic.php?topic_view=threads&p=260688&t=27385 Re: When will come a new Toga Engine?] by [[Ryan Benitez]], [[CCC]], April 10, 2009
* [http://www.talkchess.com/forum/viewtopic.php?t=29528 Toga / Fruit historical question] by [[Vladimir Medvedev]], [[CCC]], August 25, 2009
==2010==
* [http://www.talkchess.com/forum/viewtopic.php?t=33795 Question about Fruit 2.1 code] by [[Harm Geert Muller]], [[CCC]], April 14, 2010
* [http://www.talkchess.com/forum/viewtopic.php?t=34780 Cluster Toga based on Fruit Source Code] by [[Kai Himstedt]], [[CCC]], June 07, 2010 » [[Cluster Toga]]
* [http://www.talkchess.com/forum/viewtopic.php?t=36907 Question about Fruit] by Peter Kasinski, [[CCC]], December 02, 2010
* [http://www.open-chess.org/viewtopic.php?f=3&t=815 Brief Q&A about Rybka 1.0 Beta and Fruit 2.1] by [[Mark Watkins|BB+]], [[Computer Chess Forums|OpenChess Forum]], December 14, 2010
==2011==
* [http://www.talkchess.com/forum/viewtopic.php?t=37777 Interview with Fabien (from the year 2005) ...] by [[Frank Quisinsky]], [[CCC]], January 25, 2011
* [http://www.talkchess.com/forum/viewtopic.php?t=37789 GNU Chess 6 (= Fruit)] by [[Harm Geert Muller]], [[CCC]], January 25, 2011 <ref>[http://www.gnu.org/software/chess/chess.html GNU Chess - Free Software Foundation]</ref>
* [http://www.open-chess.org/viewtopic.php?f=5&t=1104 Feb 12 version: Rybka 1.0 Beta / Fruit 2.1 document] by [[Mark Watkins|BB+]], [[Computer Chess Forums|OpenChess Forum]], February 12, 2011
* [http://www.chessvibes.com/?q=reports/attack-of-the-clones Attack of the clones | ChessVibes] by [[David Levy]], 19 February, 2011
* [http://www.chessvibes.com/?q=reports/programmers-write-open-letter-about-rybka-fruit-issue Programmers write open letter about Rybka-Fruit issue | ChessVibes] by [http://www.chessvibes.com/?q=peterdoggers Peter Doggers], March 01, 2011
* [http://www.hiarcs.net/forums/viewtopic.php?t=4038 Open letter to the ICGA about the Rybka-Fruit issue] by [[Harvey Williamson]], [[Computer Chess Forums|Hiarcs Forum]], March 01, 2011
* [http://www.open-chess.org/viewtopic.php?f=3&t=1175 Programmers Open Letter to ICGA on Rybka/Fruit] by [[Mark Watkins|BB+]], [[Computer Chess Forums|OpenChess Forum]], March 01, 2011 » [[ICGA Investigations]]
* [http://www.open-chess.org/viewtopic.php?f=5&t=1353 Loop 2007 / Fruit 2.1] by [[Mark Watkins|BB+]], [[Computer Chess Forums|OpenChess Forum]], Apr 18, 2011 » [[Loop (Program)|Loop]]
==2012 ...==
* [http://www.open-chess.org/viewtopic.php?f=5&t=1795 Fruit/Rybka timeline] by [[Mark Watkins|BB+]], [[Computer Chess Forums|OpenChess Forum]], January 09, 2012
* [http://www.talkchess.com/forum/viewtopic.php?t=51638 Fruit 1.0 anniversary] by [[Fabien Letouzey]], [[CCC]], March 17, 2014
=External Links=
==Chess Engine==
===Fruit===
* [http://www.fruitchess.com/ Fruit - pure playing strength]
: [[FILE:fruit-logo.jpg|none|border|text-bottom|link=http://www.fruitchess.com/index.htm]]
* [http://arctrix.com/nas/chess/fruit/ Fruit Chess Engine by Fabien Letouzey - Fruit 2.1 source]
* [http://www.gnu.org/software/chess/chess.html GNU Chess - Free Software Foundation]
* [https://www.game-ai-forum.org/icga-tournaments/program.php?id=59 Fruit's ICGA Tournaments]
* [https://en.wikipedia.org/wiki/Fruit_%28chess_engine%29 Fruit (chess engine) from Wikipedia]
* [http://www.top-5000.nl/int/fruit.htm The alternative to Crafty], Interview with [[Fabien Letouzey]] by [[Frank Quisinsky]] April 05, 2005, from [http://www.playwitharena.com/ Free chess graphical user interface (GUI) Arena for chess engines], News-Ticker, Page 7, 96, FQ, also hosted by [[Ed Schroder|Ed Schröder]] <ref>[http://www.talkchess.com/forum/viewtopic.php?t=37777 Interview with Fabien (from the year 2005) ...] by [[Frank Quisinsky]], [[CCC]], January 25, 2011</ref>
* [http://www.chessvibes.com/?q=reports/attack-of-the-clones Attack of the clones | ChessVibes] by [[David Levy]], 19 February, 2011 » [[Rybka]], [[Strelka]]
* [http://www.computerchess.org.uk/ccrl/4040/cgi/engine_details.cgi?print=Details&eng=Fruit%202.1#Fruit_2_1 Fruit 2.1] in [[CCRL|CCRL 40/40]]
* [http://www.computerchess.org.uk/ccrl/404/cgi/engine_details.cgi?match_length=30&print=Details&each_game=1&eng=Fruit%202.1 Fruit 2.1] in [[CCRL|CCRL 40/4]]
===Fruit reloaded===
* [https://github.com/Akusari/Fruit-reloaded-public Akusari/Fruit-reloaded-public · GitHub]
* [http://www.chessprogramming.net/fruit-reloaded/ Fruit Reloaded - Computer Chess Programming] hosted by [[Steve Maughan]]
==Misc==
* [https://en.wikipedia.org/wiki/Fruit Fruit from Wikipedia]
* [https://en.wikipedia.org/wiki/Fruit_%28disambiguation%29 Fruit (disambiguation) from Wikipedia]
* [https://en.wikipedia.org/wiki/Forbidden_fruit_%28disambiguation%29 Forbidden fruit (disambiguation) from Wikipedia]
* [https://en.wikipedia.org/wiki/Forbidden_fruit Forbidden fruit from Wikipedia]
=References=
<references />
'''[[Engines|Up one Level]]'''
[[FILE:BakAfterThePerquisition1994.jpg|border|right|thumb| [[Arts#Bak|Samuel Bak]] - After the Perquisition, 1994
<ref>After the Perquisition, 1994 in [https://static1.squarespace.com/static/594044bd3a041171e0426683/t/5a12fdbec83025eab3732a02/1511194070554/Fruit+of+Knowledge1995.pdf Samual Bak - The Fruit of Knowledge] (pdf) from the [https://www.puckergallery.com/artists/#/samuel-bak/ Pucker Gallery - Samuel Bak]</ref> ]]
'''Fruit''',<br/>
until Version 2.1 [[Open Source Engines|open source]], is a groundbreaking [[UCI]] compatible chess engine developed by primary author [[Fabien Letouzey]]. It made its first appearance to the public in March 2004, when Fruit was a basic program with a very simple [[Evaluation |evaluation]] and basic [[Search|search]]. However, since then it made progress adding about 100 Elo to each new release (1.5, 2.0, 2.1 and Fruit 2.2) <ref>[http://www.fruitchess.com/about.htm Fruit - pure playing strength - Team / History]</ref>.
=Revolution=
The release of Fruit until version '''2.1''' under the [[Free Software Foundation#GPL|GNU General Public License]] was a "revolution" in computer chess in 2005 - an open source engine was "suddenly" competitive with the long time leading programs [[Shredder]] and [[Junior]], as demonstrated at the [[WCCC 2005]], where Fruit became runner up behind [[Zappa]]. After the strong [[Massy 2005]] over the board debut, and the great success of Reykjavik, where Fabien Letouzey met his professional colleagues, he decided to close the source <ref>[https://www.stmintz.com/ccc/index.php?id=444731 Re: Fruit Reykjavic] by [[Fabien Letouzey]], [[CCC]], August 24, 2005</ref> and to go commercial <ref>[https://www.stmintz.com/ccc/index.php?id=449961 Fruit commercial] by [[Fabien Letouzey]], [[CCC]], September 16, 2005</ref> - while Fruit derivatives have already appeared based on the source code of Fruit 2.1, most notably [[Toga]] by [[Thomas Gaksch]], and [[Gambit Fruit]] by [[Ryan Benitez]], who in late 2005 joint forces with Fabian for the commercial endeavor. Fabien finished his commercial computer chess career so far in 2007 <ref>[http://www.fruitchess.com/ Fruit - pure playing strength]</ref>. Fruit '''2.3+''' is non [[Free Software Foundation#GPL|GPL]] with full rights given to [[Ryan Benitez]] who continued the Fruit development porting it to [[Bitboards|bitboards]] <ref>[http://www.talkchess.com/forum/viewtopic.php?t=19164&start=1 Re: How many "official" Toga projects there is now] by [[Ryan Benitez]], [[CCC]], January 24, 2008</ref>, while Fruit 2.1 is now owned by the [[Free Software Foundation]] <ref>[http://www.talkchess.com/forum/viewtopic.php?topic_view=threads&p=260688&t=27385 Re: When will come a new Toga Engine?] by [[Ryan Benitez]] from [[CCC]], April 10, 2009</ref>, released as [[GNU Chess|GNU Chess 6]] <ref>[http://www.talkchess.com/forum/viewtopic.php?t=37789 GNU Chess 6 (= Fruit)] by [[Harm Geert Muller]], [[CCC]], January 25, 2011</ref>.
=Tournament Play=
Fruit had its strong debut at [[CCT7]], February 2005, and over the board at [[Massy 2005]] in June 2005, with the then surprising shared second place, tied with [[Chess Wizard]] behind [[AnMon]]. After the mentioned breakthrough at the [[WCCC 2005]] in Reykjavík, Fruit played the [[DOCCC 2005]], operated by new book author [[Jeroen Noomen]], who short later left the team for [[Rybka]], the [[IPCCC 2005 b]], [[CCT8]] and the [[DOCCC 2006]]. Fruit continued to play [[CCT Tournaments]] from [[CCT10]] in 2008.
=Photos & Games=
[[FILE:ShredderFruit2005.jpg|none|border|text-bottom|640px]]
[[Stefan Meyer-Kahlen]] and [[Fabien Letouzey]], [[Shredder]] - Fruit, [[WCCC 2005]] <ref>Photo by [[Gerd Isenberg]]</ref>
<pre>
[Event "WCCC 2005"]
[Site "Reykjavík, Iceland"]
[Date "2005.08.16"]
[Round "5"]
[White "Shredder"]
[Black "Fruit"]
[Result "0-1"]
1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 Nc6 5.Nc3 a6 6.Be2 d6 7.Be3 Nf6 8.f4 Be7 9.O-O Qc7
10.Qe1 O-O 11.Kh1 Nxd4 12.Bxd4 b5 13.Qg3 Bb7 14.a3 Bc6 15.Bd3 Rfd8 16.Rae1 Qb7 17.Bxf6
Bxf6 18.e5 Be7 19.Ne4 dxe5 20.fxe5 Rd5 21.Re2 Rf8 22.Nf6+ Bxf6 23.Rxf6 Rd4 24.Rh6 g6
25.Rh4 Rxh4 26.Qxh4 Qb6 27.Qf4 Rd8 28.Rf2 Rd7 29.c3 Qc7 30.Qe3 Qd8 31.Bf1 Rd1 32.Kg1 Qd5
33.Re2 a5 34.Qf2 b4 35.axb4 axb4 36.cxb4 h6 37.Re1 Rxe1 38.Qxe1 Qd4+ 39.Qf2 Qxb4 40.h3
Be4 41.Kh2 Bd5 42.Bd3 Qb7 43.Qf6 Qb6 44.Qh4 Qb8 45.Qf6 Qb7 46.Bb1 Qd7 47.Qh4 Qc7 48.Qf4
Ba8 49.b4 Qb7 50.Qd2 Kg7 51.Qb2 Qb5 52.Kg1 h5 53.Ba2 Qd3 54.Qf2 Kg8 55.Kh2 Be4 56.Qb2 h4
57.b5 g5 58.Qf2 Qc3 59.b6 Kf8 60.Kg1 Qa1+ 61.Kh2 Qxe5+ 62.Kg1 Qa1+ 63.Kh2 Qc3 64.Kg1 Ke7
65.Kh2 f5 66.Kg1 Kd7 67.Kh2 Kc6 68.Qe2 Kxb6 69.Qf2+ Kc6 70.Qe2 Kd6 71.Bc4 Qe5+ 72.Kg1 Qd4+
73.Kh2 g4 74.hxg4 fxg4 75.Qxg4 Qxc4 76.Qxh4 Qe2 77.Qd8+ Kc6 78.Qc8+ Kb5 79.Qb8+ Kc4 80.Qc7+
Kd3 81.Qd6+ Bd5 82.Qa6+ Kd2 83.Qa5+ Kc2 84.Qa4+ Bb3 85.Qd4 e5 86.Qa7 e4 87.Qc5+ Bc4 88.Qa3
Qd3 89.Qa5 e3 90.Qa4+ Qb3 91.Qe8 e2 92.Qe4+ Kb2 93.Qh4 Qc3 94.Qf2 0-1
</pre>
=Innovations=
Fruit was and still is one of the most influential didactic open source programs. It uses a 16x12 [[Vector Attacks|Vector attack]] [[Board Representation|board representation]], since Version 1.5 a 16x16 board to have a symmetric treatment of files and ranks <ref>[http://www.open-aurec.com/wbforum/viewtopic.php?f=4&t=2407&p=11195#p11109 Re: Fruit's Board Representation?] by [[Fabien Letouzey]], [[Computer Chess Forums|Winboard Forum]], April 28, 2005</ref> . Its structure and [[C]] source code was very clean and apparently bug-free due to runtime checking a lot of preconditions using [[Debugging|debug asserts]]. While [[Late Move Reductions|late move reductions]] (LMR) might be used in other programs before, Fabien's [[History Heuristic|history]] based implementation in conjunction with [[History Leaf Pruning|history leaf pruning]] made LMR very popular. Another Fruit innovation, despite not absolutely new and already a known issue, and related to what is mentioned in [[Evaluation Philosophy|evaluation philosophy]], was [[Tapered Eval|tapered evaluation]] to avoid [[Evaluation Discontinuity|discontinuity]] <ref>[https://www.stmintz.com/ccc/index.php?id=470647 Secrets of Rybka and Fruit from my point of view] by [[Sergei Markoff]], [[CCC]], December 15, 2005</ref> .
* [[Evaluation Philosophy]]
* [[History Heuristic]]
* [[History Leaf Pruning]]
* [[Late Move Reductions]]
* [[Null Move Pruning]]
* [[Tapered Eval]]
=Fruit Team=
Beside Fabien Letouzey as primary author and [[Opening Book Authors|opening book author]] [[Marc Lacrosse]], [[Ryan Benitez]] joined the Fruit-Team in December 2005. Before he developed [[Gambit Fruit]] with some interesting changes on the basis of the last open-source-version 2.1. [[Joachim Rang]] was the main tester of Fruit since its first public appearance, tuned parameters, and tested evaluation and search features <ref>[http://www.fruitchess.com/about.htm Fruit - pure playing strength - Team / History]</ref> .
* [[Fabien Letouzey]]
* [[Marc Lacrosse]] <ref>[https://www.stmintz.com/ccc/index.php?id=462330 To Fruit's author Fabien Letouzey and commercial manager Joachim Rang] by [[Marc Lacrosse]], [[CCC]], November 17, 2005</ref>
* [[Ryan Benitez]]
* [[Joachim Rang]]
<span id="Fruit64"></span>
=Fruit 64=
[[Ryan Benitez]] continued the development on the non public Fruit in 2007 <ref>[http://www.talkchess.com/forum/viewtopic.php?t=17559&start=1 Re: Question to co-Author of Fruit and Chess64, Ryan Benitez] by [[Ryan Benitez]], [[CCC]], November 03, 2007</ref>. He converted the board representation from [[Vector Attacks|vector attacks]] to [[Bitboards|bitboards]], and naturally, Fruit has become a new [[Evaluation|evaluation]] to go along with that <ref>[http://www.talkchess.com/forum/viewtopic.php?topic_view=threads&p=256307&t=26965 Re: Fruit vs. Toga poll] by [[Ryan Benitez]], [[CCC]], March 19, 2009</ref>. Fruit by Fabien Letouzey and Ryan Benitez played the [[CCT10]], the [[CCT11]], where it became shared winner along with [[Bright]] after the later [[Rybka]] disqualification <ref>[https://cctchess.com/previous-events/cct-11/results/ CCT11: Bright by Allard Siemelink and Fruit by Fabien Letouzey are Co-Champions]</ref>, and the [[CCT13]] in 2011.
=Influence=
Many programmers took a lot of ideas and implementation details from Fruit, as noted by [[Vasik Rajlich]] <ref>[http://www.top-5000.nl/int/rybka.htm Interview with Vasik Rajlich] by [[Christopher Conkie]], [[Michael Diosi]], [[Frank Quisinsky]] & [[Alexander Schmidt]], December 20, 2005, hosted by [[Ed Schroder|Ed Schröder]]</ref> :
[[Alexander Schmidt]]:
The increase in playing strength of the latest chess engines is unbelieveable. We have since some time with Fruit 2.1 by Fabien Letouzey a very strong open source engine. Do you see a relation between the published sources of such a strong engine and the increase of strength in computer chess in general? How much influence do the ideas of Fruit have on the future of computerchess?
[[Vasik Rajlich]]:
Yes, the publication of Fruit 2.1 was huge. Look at how many engines took a massive jump in its wake: [[Rybka]], [[Hiarcs]], [[Fritz]], [[Zappa]], [[Spike]], [[List (program)|List]], and so on. I went through the Fruit 2.1 source code forwards and backwards and took many things.
<span id="reloaded"></span>
=Fruit Reloaded=
In March 2014, ten years after the initial Fruit 1.0 release, [[Daniel Mehrmann]] initiated a "let's update Fruit" called [[Fruit Reloaded]] <ref>[http://www.talkchess.com/forum/viewtopic.php?t=51638 Fruit 1.0 anniversary] by [[Fabien Letouzey]], [[CCC]], March 17, 2014</ref>. With some help from [[Ryan Benitez]], the aim is to add [[Parallel Search|SMP]] to Fruit and upgrade search and [[Evaluation|evaluation]] with modern techniques <ref>[https://github.com/Akusari/Fruit-reloaded-public Akusari/Fruit-reloaded-public · GitHub]</ref> <ref>[http://www.chessprogramming.net/fruit-reloaded/ Fruit Reloaded - Computer Chess Programming] hosted by [[Steve Maughan]]</ref>. Simultaneously, Fabien Letouzey waved goodbye to Fruit and published his new [[Open Source Engines|open source engine]] [[Senpai]], also with [[Ryan Benitez]] and [[Joachim Rang]] involved <ref>[http://www.talkchess.com/forum/viewtopic.php?t=51637 Senpai 1.0 (new engine)] by [[Fabien Letouzey]], [[CCC]], March 17, 2014</ref>.
=Derivatives=
* [[Cluster Toga]]
* [[Cyclone]]
* [[Fruit Reloaded]]
* [[Gambit Fruit]]
* [[GNU Chess|GNU Chess 6]]
* [[GridChess]]
* [[Lion]]
* [[Patriot]] 2.0
* [[Rybka]]
* [[Strelka]]
* [[Toga]]
=See also=
* [[Chess-64]]
* [[Cipollino]]
* [[Various Classifications#Food|Food]]
* [[ICGA Investigations]]
: [[Rybka Controversy]]
* [[Senpai]]
* [[WCCC 2005]]
=Publications=
* [[Mark Watkins]] ('''2011'''). ''A comparison of Rybka 1.0 Beta and Fruit 2.1'', [http://www.open-chess.org/download/file.php?id=272 pdf, February 12, 2011 Version] <ref>[http://www.open-chess.org/viewtopic.php?f=5&t=1104 Feb 12 version: Rybka 1.0 Beta / Fruit 2.1 document] by [[Mark Watkins]], [[Computer Chess Forums|OpenChess General Forum]], February 12, 2011</ref>
* [[Mark Watkins]] ('''2011'''). ''A comparison of Rybka 1.0 Beta and Fruit 2.1'', [http://www.open-chess.org/download/file.php?id=304 pdf, February 24, 2011 Version]
* [[Mark Watkins]] ('''2011'''). ''A comparison of Rybka 1.0 Beta and Fruit 2.1'', [http://www.open-chess.org/download/file.php?id=332 pdf, March 11, 2011 Version] » [[Rybka]]
* [[Jaap van den Herik]], [[Krzysztof Siewicz]] ('''2011'''). ''Open Source has a Price''. [[ICGA Journal#34_2|ICGA Journal, Vol. 34, No. 2]]
=Forum Posts=
==2004==
* [https://www.stmintz.com/ccc/index.php?id=353818 Fruit Results], by Afzal Siddique, [[CCC]], March 10, 2004
* [https://www.stmintz.com/ccc/index.php?id=353927 Fruit: first observations. Not a coconut yet, a budding pomegranate?] by [[Đorđe Vidanović]], [[CCC]], March 10, 2004
* [https://www.stmintz.com/ccc/index.php?id=354012 Fruit - Question for Fabien] by [[Dan Honeycutt]], [[CCC]], March 11, 2004 » [[Node Types]], [[Transposition Table]], [[Principal variation]], [[Principal Variation Search]]
* [https://www.stmintz.com/ccc/index.php?id=354194 What makes Fruit so strong?] by [[Steve Maughan]], March 12, 2004
* [https://www.stmintz.com/ccc/index.php?id=354644 Fruit, trying to answer various missed posts] by [[Fabien Letouzey]], [[CCC]], March 15, 2004
* [https://www.stmintz.com/ccc/index.php?id=355103 Fruit 1.0 UCI (with source code) now available] by [[Fabien Letouzey]], [[CCC]], March 17, 2004
* [https://www.stmintz.com/ccc/index.php?id=356705 Fruit 1.0 64-bit] by [[Slater Wold]], [[CCC]], March 26, 2004
* [https://www.stmintz.com/ccc/index.php?id=368930 Fruit 1.5 UCI available (Windows/Linux/MacOS + source code)!] by [[Fabien Letouzey]], [[CCC]], June 04, 2004
* [https://www.stmintz.com/ccc/index.php?id=369055 Fruit 1.5 released!] by [[Joachim Rang]], [[CCC]], June 05, 2004
* [https://www.stmintz.com/ccc/index.php?id=371315 Fruit 1.5 Hash Hit Percentage] by [[Robert Allgeuer]], [[CCC]], June 19, 2004
* [https://www.stmintz.com/ccc/index.php?id=378541 null move question(Fruit)] by [[Jan Kaan|Jan K.]], [[CCC]], July 22, 2004
* [https://www.stmintz.com/ccc/index.php?id=402402 Fruit 2.0 released!] by [[Joachim Rang]], [[CCC]], December 24, 2004
==2005==
* [https://www.stmintz.com/ccc/index.php?id=404043 Fruit2 = Ruffian with source code!] by [[Jouni Uski]], [[CCC]], January 04, 2005
* [https://www.stmintz.com/ccc/index.php?id=405159 Fruit 2 and endgame play] by [[Jouni Uski]], [[CCC]], January 12, 2005
* [http://www.open-aurec.com/wbforum/viewtopic.php?f=4&t=2407&p=11195 Fruit's Board Representation?] by [[Steve Maughan]], [[Computer Chess Forums|Winboard Programming Forum]], April 27, 2005
* [https://www.stmintz.com/ccc/index.php?id=426309 why is Patriot 2.0 beta ?] by [[Matthias Gemuh]], [[CCC]], May 16, 2005 » [[Patriot]]
: [https://www.stmintz.com/ccc/index.php?id=426427 Re: why is Patriot 2.0 beta ?] by [[Fabien Letouzey]], [[CCC]], May 17, 2005
* [https://www.stmintz.com/ccc/index.php?id=431280 Re: What makes Fruit and Fruit-Toga so strong?] by [[Fabien Letouzey]], [[CCC]], June 15, 2005
* [http://www.open-aurec.com/wbforum/viewtopic.php?f=4&t=2869&p=13538 understanding fruit] by [[Uri Blass]], [[Computer Chess Forums|Winboard Programming Forum]], June 18, 2005
* [https://www.stmintz.com/ccc/index.php?id=432238 Temptation for Fabien: going commercial] by [[Matthias Gemuh]], [[CCC]], June 20, 2005
* [https://www.stmintz.com/ccc/index.php?id=438699 Fruit on Pocket PC] by [[Alain Zanchetta]], [[CCC]], July 27, 2005 » [[CEBoard]], [[Pocket PC]]
* [https://www.stmintz.com/ccc/index.php?id=440956 Re: Some details] by [[Joachim Rang]], [[CCC]], August 09, 2005
* [https://www.stmintz.com/ccc/index.php?id=444731 Re: Fruit Reykjavic] by [[Fabien Letouzey]], [[CCC]], August 24, 2005
* [https://www.stmintz.com/ccc/index.php?id=449961 Fruit commercial] by [[Fabien Letouzey]], [[CCC]], September 16, 2005
* [https://www.stmintz.com/ccc/index.php?id=460591 Re: Fact is also that Fruit went commercial] by [[Eduard Nemeth]], [[CCC]], November 09, 2005
* [https://www.stmintz.com/ccc/index.php?id=461801 Re: Gambit Fruit ?] by [[Ryan Benitez|Ryan B.]], [[CCC]], November 15, 2005
* [https://www.stmintz.com/ccc/index.php?id=461958 Has anyone tested Gambit Fruit with Rebel Reductions on?] by [[Ryan Benitez|Ryan B.]], [[CCC]], November 15, 2005 » [[Reductions]], [[Rebel]] <ref>[http://www.top-5000.nl/authors/rebel/chess840.htm#REDUCTIONS Programmer Corner - How Rebel Plays Chess - Reductions] by [[Ed Schroder|Ed Schröder]], [http://members.home.nl/matador/Inside%20Rebel.pdf pdf reprint]</ref>
* [https://www.stmintz.com/ccc/index.php?id=462330 To Fruit's author Fabien Letouzey and commercial manager Joachim Rang] by [[Marc Lacrosse]], [[CCC]], November 17, 2005
* [https://www.stmintz.com/ccc/index.php?id=462901 Gambit Fruit Beta 3 available] by [[Ryan Benitez|Ryan B.]], [[CCC]], November 19, 2005
* [https://www.stmintz.com/ccc/index.php?id=464128 A. STEEN vs. FRUIT 2.2.1 {Posted at request of Graham Banks & M. Monge}] by A. Steen, [[CCC]], November 24, 2005
* [https://www.stmintz.com/ccc/index.php?id=470607 Unmasking the Secrets of Rybka and Fruit] by [[Stuart Cracraft]], [[CCC]], December 15, 2005
* [https://www.stmintz.com/ccc/index.php?id=470647 Secrets of Rybka and Fruit from my point of view] by [[Sergei Markoff]], [[CCC]], December 15, 2005
==2006==
* [https://www.stmintz.com/ccc/index.php?id=478190 SSDF(Fruit 2.2.1 - Ruffian 1.0.1)A1200, 2½-2½, ended 26-14] by [[Tony Hedlund]], [[CCC]], January 09, 2006 » [[SSDF]], [[Ruffian]]
* [https://www.stmintz.com/ccc/index.php?id=478224 not correct information in fruit's site] by [[Uri Blass]], [[CCC]], January 09, 2006
* [https://www.stmintz.com/ccc/index.php?id=479189 congratulations to gambit-fruit!] by [[Thorsten Czub]], [[CCC]], January 13, 2006 » [[Gambit Fruit]]
* [https://www.stmintz.com/ccc/index.php?id=479366 Rybka and Fruit on Chessbase] by [[Walter Faxon]], [[CCC]], January 14, 2006 » [[Rybka]], [[ChessBase]]
* [https://www.stmintz.com/ccc/index.php?id=479410 SSDF(Fritz 9 - Fruit 2.2.1)A1200, 1.5-1.5, ended 21-19] by [[Tony Hedlund]], [[CCC]], January 14, 2006 » [[SSDF]], [[Fritz]]
* [https://www.stmintz.com/ccc/index.php?id=481382 SSDF Fruit 2.2.1 A1200 - Junior 7.0 A1200 Ended: 38.5-8.5] by [[Paul Petersson]], [[CCC]], January 22, 2006 » [[SSDF]], [[Junior]]
* [https://www.stmintz.com/ccc/index.php?id=483065 SSDF(Hiarcs 10 - Fruit 2.2.1)A1200, 1-2, ended 19-21] by [[Tony Hedlund]], [[CCC]], January 29, 2006 » [[SSDF]], [[Hiarcs]]
* [https://www.stmintz.com/ccc/index.php?id=489916 What are the moves of the loss of fruit against hiarcs?] by [[Uri Blass]], [[CCC]], February 26, 2006 » [[CCT8]]
* [https://www.stmintz.com/ccc/index.php?id=491661 Fruit depth] by [[Stuart Cracraft]], [[CCC]], March 06, 2006 » [[Depth]], [[Branching Factor]]
* [https://www.stmintz.com/ccc/index.php?id=492114 Toga II 1.2 Beta2a based on Fruit released] by [[Thomas Gaksch]], [[CCC]], March 08, 2006
==2007==
* [http://www.talkchess.com/forum/viewtopic.php?t=13446 SSDF(Hiarcs 11.1 - Fruit 2.2.1)A1200, 12-7, ended 24-24] by [[Tony Hedlund]], April 28, 2007 » [[SSDF]], [[Hiarcs]]
* [http://www.talkchess.com/forum/viewtopic.php?t=14661 SSDF(Zap!Chess Zanzibar-Fruit 2.2.1)A1200 3½-2½ ende 22½-17½] by [[Tony Hedlund]], June 24, 2007 » [[SSDF]], [[Zappa]]
* [http://www.talkchess.com/forum/viewtopic.php?t=15076 Fruit, Rybka, Strelka final conclusion! (I hope)] by [[Michael Sherwin]], [[CCC]], July 13, 2007 » [[Rybka]], [[Strelka]]
* [http://www.talkchess.com/forum/viewtopic.php?t=15094 What is Fruit? Fabien explains!] by [[Michael Sherwin]], [[CCC]], July 14, 2007
* [http://www.talkchess.com/forum/viewtopic.php?t=15219 Fruit and History Reductions] by [[Ed Schroder|Ed Schröder]], [[CCC]], July 19, 2007 » [[Late Move Reductions]]
* [http://www.talkchess.com/forum/viewtopic.php?t=15249 Fruit availability - 2 questions] by Kaj Soderberg, [[CCC]], July 20, 2007
: [http://www.talkchess.com/forum/viewtopic.php?t=15249&start=6 Re: Fruit availability - 2 questions] by [[Ryan Benitez]], [[CCC]], July 21, 2007
* [http://www.talkchess.com/forum/viewtopic.php?t=15310 Fruit is already a free chess engine...] by [[Dr. Wael Deeb|Dr.Wael Deeb]], [[CCC]], July 23, 2007
* [http://www.talkchess.com/forum/viewtopic.php?t=15328 Fruit 2.2.1 : 2687] by [[Patrick Buchmann]], [[CCC]], July 24, 2007
* [http://www.talkchess.com/forum/viewtopic.php?t=15358 Fruit 2.3 released] by [[Ryan Benitez]], [[CCC]], July 26, 2007
* [http://www.talkchess.com/forum/viewtopic.php?t=15488 Fruit 2.3 : 2689] by [[Patrick Buchmann]], [[CCC]], July 31, 2007
* [http://www.talkchess.com/forum/viewtopic.php?t=15533 Fruit 2.3.1 released] by [[Ryan Benitez]], [[CCC]], August 02, 2007
* [http://www.talkchess.com/forum/viewtopic.php?t=15626 Fruit 2.3.1 : 2673] by [[Patrick Buchmann]], [[CCC]], August 06, 2007
* [http://www.talkchess.com/forum/viewtopic.php?t=15981 Is Toga still weaker than Fruit?] by [[Jouni Uski]], [[CCC]], August 23, 2007
* [http://www.talkchess.com/forum/viewtopic.php?t=17260 Fruit2.3.1 stalemate bug] by [[Uri Blass]], [[CCC]], October 21, 2007
* [http://www.talkchess.com/forum/viewtopic.php?t=17559 Question to co-Author of Fruit and Chess64, Ryan Benitez] by [[Swaminathan Natarajan|Swaminathan]], [[CCC]], November 03, 2007
* [http://www.talkchess.com/forum/viewtopic.php?t=18391 Fruit SMP 2.3.4e Beta] by Daniel Charles, [[CCC]], December 15, 2007
==2008==
* [http://www.talkchess.com/forum/viewtopic.php?t=19164&start=1 Re: How many "official" Toga projects there is now] by [[Ryan Benitez]], [[CCC]], January 24, 2008
* [http://www.talkchess.com/forum/viewtopic.php?t=20106 Has Fruit finaly surpassed Rybka!?] by [[Dr. Wael Deeb|Dr.Wael Deeb]], [[CCC]], March 11, 2008
* [http://www.talkchess.com/forum/viewtopic.php?t=22359 Fruit 2.1 pruning] by [[Chua Kong Sian|kongsian]], [[CCC]], July 15, 2008 » [[Pruning]]
* [http://www.talkchess.com/forum/viewtopic.php?t=23095 Fruit 2.1 vs Strelka 2.0] by [[Norman Schmidt]], [[CCC]], August 18, 2008
* [http://www.talkchess.com/forum/viewtopic.php?t=23172 counting similiarities between strelka2.0 and fruit2.1] by [[Uri Blass]], [[CCC]], August 22, 2008
* [http://www.talkchess.com/forum/viewtopic.php?t=24504 Strelka = Rybka 1.0 =Fruit 2.1 = Toga?? Oh how disappointing] by [[Oliver Brausch]], [[CCC]], October 21, 2008 » [[Strelka]], [[Rybka]], [[Toga]]
* [http://www.computerchess.info/tdbb/phpBB3/viewtopic.php?f=9&t=225&start=0&st=0&sk=t&sd=a Chess engine oldies upgrades] by [[Denis Mendoza|Denis P. Mendoza]], [[Computer Chess Forums|Toga Developers Discussion Board]], December 30, 2008 » [[Gambit Fruit]]
==2009==
* [http://www.talkchess.com/forum/viewtopic.php?t=26282 posix source for GambitFruit4bxSE ?] by Martin Helmer, [[CCC]], January 28, 2009
* [http://www.talkchess.com/forum/viewtopic.php?t=26965 Fruit vs. Toga poll] by [[Miguel A. Ballicora]], [[CCC]], March 11, 2009
: [http://www.talkchess.com/forum/viewtopic.php?topic_view=threads&p=256307&t=26965 Re: Fruit vs. Toga poll] by [[Ryan Benitez]], [[CCC]], March 19, 2009
* [http://www.talkchess.com/forum/viewtopic.php?t=27186 Error in Fruit 2.1 source?] by [[Ernest Bonnem]], [[CCC]], March 25, 2009
* [http://www.talkchess.com/forum/viewtopic.php?topic_view=threads&p=260688&t=27385 Re: When will come a new Toga Engine?] by [[Ryan Benitez]], [[CCC]], April 10, 2009
* [http://www.talkchess.com/forum/viewtopic.php?t=29528 Toga / Fruit historical question] by [[Vladimir Medvedev]], [[CCC]], August 25, 2009
==2010==
* [http://www.talkchess.com/forum/viewtopic.php?t=33795 Question about Fruit 2.1 code] by [[Harm Geert Muller]], [[CCC]], April 14, 2010
* [http://www.talkchess.com/forum/viewtopic.php?t=34780 Cluster Toga based on Fruit Source Code] by [[Kai Himstedt]], [[CCC]], June 07, 2010 » [[Cluster Toga]]
* [http://www.talkchess.com/forum/viewtopic.php?t=36907 Question about Fruit] by Peter Kasinski, [[CCC]], December 02, 2010
* [http://www.open-chess.org/viewtopic.php?f=3&t=815 Brief Q&A about Rybka 1.0 Beta and Fruit 2.1] by [[Mark Watkins|BB+]], [[Computer Chess Forums|OpenChess Forum]], December 14, 2010
==2011==
* [http://www.talkchess.com/forum/viewtopic.php?t=37777 Interview with Fabien (from the year 2005) ...] by [[Frank Quisinsky]], [[CCC]], January 25, 2011
* [http://www.talkchess.com/forum/viewtopic.php?t=37789 GNU Chess 6 (= Fruit)] by [[Harm Geert Muller]], [[CCC]], January 25, 2011 <ref>[http://www.gnu.org/software/chess/chess.html GNU Chess - Free Software Foundation]</ref>
* [http://www.open-chess.org/viewtopic.php?f=5&t=1104 Feb 12 version: Rybka 1.0 Beta / Fruit 2.1 document] by [[Mark Watkins|BB+]], [[Computer Chess Forums|OpenChess Forum]], February 12, 2011
* [http://www.chessvibes.com/?q=reports/attack-of-the-clones Attack of the clones | ChessVibes] by [[David Levy]], 19 February, 2011
* [http://www.chessvibes.com/?q=reports/programmers-write-open-letter-about-rybka-fruit-issue Programmers write open letter about Rybka-Fruit issue | ChessVibes] by [http://www.chessvibes.com/?q=peterdoggers Peter Doggers], March 01, 2011
* [http://www.hiarcs.net/forums/viewtopic.php?t=4038 Open letter to the ICGA about the Rybka-Fruit issue] by [[Harvey Williamson]], [[Computer Chess Forums|Hiarcs Forum]], March 01, 2011
* [http://www.open-chess.org/viewtopic.php?f=3&t=1175 Programmers Open Letter to ICGA on Rybka/Fruit] by [[Mark Watkins|BB+]], [[Computer Chess Forums|OpenChess Forum]], March 01, 2011 » [[ICGA Investigations]]
* [http://www.open-chess.org/viewtopic.php?f=5&t=1353 Loop 2007 / Fruit 2.1] by [[Mark Watkins|BB+]], [[Computer Chess Forums|OpenChess Forum]], Apr 18, 2011 » [[Loop (Program)|Loop]]
==2012 ...==
* [http://www.open-chess.org/viewtopic.php?f=5&t=1795 Fruit/Rybka timeline] by [[Mark Watkins|BB+]], [[Computer Chess Forums|OpenChess Forum]], January 09, 2012
* [http://www.talkchess.com/forum/viewtopic.php?t=51638 Fruit 1.0 anniversary] by [[Fabien Letouzey]], [[CCC]], March 17, 2014
=External Links=
==Chess Engine==
===Fruit===
* [http://www.fruitchess.com/ Fruit - pure playing strength]
: [[FILE:fruit-logo.jpg|none|border|text-bottom|link=http://www.fruitchess.com/index.htm]]
* [http://arctrix.com/nas/chess/fruit/ Fruit Chess Engine by Fabien Letouzey - Fruit 2.1 source]
* [http://www.gnu.org/software/chess/chess.html GNU Chess - Free Software Foundation]
* [https://www.game-ai-forum.org/icga-tournaments/program.php?id=59 Fruit's ICGA Tournaments]
* [https://en.wikipedia.org/wiki/Fruit_%28chess_engine%29 Fruit (chess engine) from Wikipedia]
* [http://www.top-5000.nl/int/fruit.htm The alternative to Crafty], Interview with [[Fabien Letouzey]] by [[Frank Quisinsky]] April 05, 2005, from [http://www.playwitharena.com/ Free chess graphical user interface (GUI) Arena for chess engines], News-Ticker, Page 7, 96, FQ, also hosted by [[Ed Schroder|Ed Schröder]] <ref>[http://www.talkchess.com/forum/viewtopic.php?t=37777 Interview with Fabien (from the year 2005) ...] by [[Frank Quisinsky]], [[CCC]], January 25, 2011</ref>
* [http://www.chessvibes.com/?q=reports/attack-of-the-clones Attack of the clones | ChessVibes] by [[David Levy]], 19 February, 2011 » [[Rybka]], [[Strelka]]
* [http://www.computerchess.org.uk/ccrl/4040/cgi/engine_details.cgi?print=Details&eng=Fruit%202.1#Fruit_2_1 Fruit 2.1] in [[CCRL|CCRL 40/40]]
* [http://www.computerchess.org.uk/ccrl/404/cgi/engine_details.cgi?match_length=30&print=Details&each_game=1&eng=Fruit%202.1 Fruit 2.1] in [[CCRL|CCRL 40/4]]
===Fruit reloaded===
* [https://github.com/Akusari/Fruit-reloaded-public Akusari/Fruit-reloaded-public · GitHub]
* [http://www.chessprogramming.net/fruit-reloaded/ Fruit Reloaded - Computer Chess Programming] hosted by [[Steve Maughan]]
==Misc==
* [https://en.wikipedia.org/wiki/Fruit Fruit from Wikipedia]
* [https://en.wikipedia.org/wiki/Fruit_%28disambiguation%29 Fruit (disambiguation) from Wikipedia]
* [https://en.wikipedia.org/wiki/Forbidden_fruit_%28disambiguation%29 Forbidden fruit (disambiguation) from Wikipedia]
* [https://en.wikipedia.org/wiki/Forbidden_fruit Forbidden fruit from Wikipedia]
=References=
<references />
'''[[Engines|Up one Level]]'''
