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an [[UCI]] compatible [[:Category:Open Source|open source]] chess engine developed by [[Tord Romstad]], [[Marco Costalba]], [[Joona Kiiski]] and [[Gary Linscott]] <ref>[http://www.talkchess.com/forum/viewtopic.php?t=58779 Stockfish 7] by [[Joona Kiiski]], [[CCC]], January 02, 2016</ref>, licensed under the [[Free Software Foundation#GPL|GPL v3.0]]. Marco forked the project from version 2.1 of Tord's engine [[Glaurung]], first announced by Marco in November 8, 2008 <ref>[http://www.talkchess.com/forum/viewtopic.php?t=24675 Stockfish 1.0] by [[Marco Costalba]], [[CCC]], November 02, 2008</ref>, and in early 2009 Joona's [[Smaug]], a further Glaurung 2.2 derivative, was incorporated <ref>[http://www.talkchess.com/forum/viewtopic.php?t=26971&start=1 Re: Smaug: a new chess engine based on glaurung] by [[Marco Costalba]], [[CCC]], March 12, 2009</ref> . Starting out among the top twenty engines, Stockfish has quickly climbed in [[Playing Strength|strength]] to become the world strongest chess entity as of 2018 - at least concerning the [[AlphaZero]] hype <ref>[[David Silver]], [[Thomas Hubert]], [[Julian Schrittwieser]], [[Ioannis Antonoglou]], [[Matthew Lai]], [[Arthur Guez]], [[Marc Lanctot]], [[Laurent Sifre]], [[Dharshan Kumaran]], [[Thore Graepel]], [[Timothy Lillicrap]], [[Karen Simonyan]], [[Demis Hassabis]] ('''2017'''). ''Mastering Chess and Shogi by Self-Play with a General Reinforcement Learning Algorithm''. [https://arxiv.org/abs/1712.01815 arXiv:1712.01815]</ref>, public available chess entity. The name "Stockfish" reflects the ancestry of the engine. Tord is Norwegian and Marco Italian, and there is a long history of [https://en.wikipedia.org/wiki/Stockfish stockfish] trade from Norway to Italy (to Marco's home town of [https://en.wikipedia.org/wiki/Vicenza Vicenza], in fact). Stockfish also referred another famous "little fish", the then strongest chess engine [[Rybka]]. In 2011, Marco Costalba and Joona Kiiski stepped down as Stockfish maintainers <ref>[http://www.talkchess.com/forum/viewtopic.php?t=40610 Stockfish on github] by [[Marco Costalba]], [[CCC]], October 02, 2011</ref>. From that, the project is being developed and maintained by the [[:Category:Stockfish Contributor|Stockfish community]].

In 2011, Marco Costalba and Joona Kiiski stepped down as Stockfish maintainers <ref>[http://www.talkchess.com/forum/viewtopic.php?t=40610 Stockfish on github] by [[Marco Costalba]], [[CCC]], October 02, 2011</ref>. From that, the project is being developed and maintained by the [[:Category:Stockfish Contributor|Stockfish community]]. A synergy effect with the [[Shogi]] community led to the promising branch of [[Stockfish NNUE]], courtesy of [[Hisayori Noda|Nodchip]], who introduced [[NNUE]] to Stockfish in 2019 <ref>[http://www.talkchess.com/forum3/viewtopic.php?f=2&t=74059 Stockfish NN release (NNUE)] by [[Henk Drost]], [[CCC]], May 31, 2020</ref>. On September 02, 2020, '''Stockfish 12''' was released with a huge jump in [[Playing Strength|playing strength]] due to NNUE and further [[Automated Tuning|tuning]] of the engine <ref>[https://blog.stockfishchess.org/postblog/6281728108529254402020/stockfish-12 / Stockfish 12], The Stockfish Team, [https://blog.stockfishchess.org/ Stockfish Blog], September 02, 2020</ref>. The release of '''Stockfish 13''' on February 19, 2021, has been triggered by the start of sales of the [[Fat Fritz#Fat Fritz 2|Fat Fritz 2]] engine by [[ChessBase]], based on a recent development version of Stockfish with minor modifications <ref>[https://blog.stockfishchess.org/postblog/6435707071424921602021/stockfish-13 / Stockfish 13], The Stockfish Team, February 19, 2021</ref>. '''Stockfish 14''', released on July 02, 2021, further improved due to efforts by [[Tomasz Sobczyk]] and [[Gary Linscott]] in designing a new [[Stockfish NNUE#HalfKA|NNUE architecture]] in conjunction with a [[GPU]] accelerated trainer written in [https://en.wikipedia.org/wiki/PyTorch PyTorch]. Further, the collaboration with the [[Leela Chess Zero]] team payed off, in providing billions of positions to train the new NNUE <ref>[https://stockfishchess.org/blog/2021/stockfish-14/ Stockfish 14], The Stockfish Team, July 02, 2021</ref>.

Since April 2017 the interactive '''Stockfish Evaluation Guide''' is available to explore Stockfish's [[Evaluation|evaluation]] with a [[JavaScript]] implementation running in a [https://en.wikipedia.org/wiki/Web_browser browser] <ref>[http://www.talkchess.com/forum/viewtopic.php?t=64025&start=27 Re: How far away are we from deep learning Stockfish, Komodo] by [[Gary Linscott|Gary]], [[CCC]], May 21, 2017</ref> . One may enter a [[Forsyth-Edwards Notation|FEN]] string of a [[Chess Position|position]], to get the resulting [[Score|score]] of the main evaluation term considering the [[Game Phases|game phases]] within its [[Tapered Eval|tapered evaluation]], and may navigate through the tree of subterms and features with its particular characteristics for the given position <ref>[https://hxim.github.io/Stockfish-Evaluation-Guide/ Stockfish Evaluation Guide]</ref>, also supporting [[Stockfish NNUE]] nets <ref>[https://hxim.github.io/Stockfish-Evaluation-Guide/?p=nnue Stockfish Evaluation Guide - NNUE]</ref> .

* [[Piece-Lists]] until Stockfish 12 <ref>[https://github.com/official-stockfish/Stockfish/blob/sf_12/src/position.h#L193 Stockfish/position.h at sf_12 · official-stockfish/Stockfish · GitHub]</ref> <ref>[https://github.com/official-stockfish/Stockfish/pull/3247 Remove piece lists by syzygy1 · Pull Request #3247 · official-stockfish/Stockfish · GitHub]</ref> <ref>[http://www.talkchess.com/forum3/viewtopic.php?f=7&t=69364&start=12 Re: piece lists advantage with bit-boards?] by [[Ronald de Man]], [[CCC]], December 26, 2018</ref>

* [[NNUE]]** [[Stockfish NNUE#HalfKP|HalfKP]] (Stockfish 12)** [[Stockfish NNUE#HalfKA|HalfKAv2]] (Stockfish 14): ''See also'' [[Evaluation Philosophy]] <ref>[http://www.talkchess.com/forum/viewtopic.php?topic_view=threads&p=135133&t=15504 The Art of Evaluation] by [[Tord Romstad]], [[CCC]], August 2, 2007</ref> <ref>[https://hxim.github.io/Stockfish-Evaluation-Guide/ Stockfish Evaluation Guide]</ref> and [[NNUE]]

* [https://blog.stockfishchess.org/postblog/1526995581422016/stockfish-8 / Stockfish 8], November 01, 2016* [https://blog.stockfishchess.org/postblog/1806908341472018/stockfish-9 / Stockfish 9], February 09, 2018* [https://blog.stockfishchess.org/postblog/1806910112372018/stockfish-10 / Stockfish 10], December 01, 2018

* [https://blog.stockfishchess.org/postblog/1903989913022020/stockfish-11 / Stockfish 11], The Stockfish Team, January 15, 2020* [https://blog.stockfishchess.org/postblog/6258280913438965772020/introducing-nnue-evaluation / Introducing NNUE Evaluation], August 07, 2020* [https://blog.stockfishchess.org/postblog/6281728108529254402020/stockfish-12 / Stockfish 12], The Stockfish Team, September 02, 2020* [https://blog.stockfishchess.org/postblog/6435707071424921602021/stockfish-13 / Stockfish 13], The Stockfish Team, February 19, 2021* [https://stockfishchess.org/blog/2021/stockfish-14/ Stockfish 14], The Stockfish Team, July 02, 2021* [https://stockfishchess.org/blog/2021/our-lawsuit-against-chessbase/ Our lawsuit against ChessBase], The Stockfish Team, July 20, 2021 » [[ChessBase]], [[Fat Fritz#Fat Fritz 2|Fat Fritz 2]], [[Houdini#Stockfish|Houdini 6]]* [https://stockfishchess.org/blog/2021/stockfish-14-1/ Stockfish 14.1], The Stockfish Team, October 28, 2021