Four years later, Costalba, inspired by the strong open-source engine, decided to fork the project. The program originated from Glaurung, an open-source chess engine created by Romstad and first released in 2004.
Release versions and development versions are available as C++ source code and as precompiled versions for Microsoft Windows, macOS, Linux 32-bit/64-bit and Android. Both and Lichess provide Stockfish in this form in addition to a server-side program. Stockfish can be compiled to WebAssembly or JavaScript, allowing it to run in the browser. Other Stockfish-compatible graphical user interfaces (GUIs) include Fritz, Arena, Stockfish for Mac, and P圜hess. On mobile, it has been bundled with the Stockfish app, SmallFish and Droidfish. On desktop, it is the default chess engine bundled with the Internet Chess Club interface programs BlitzIn and Dasher. Stockfish has been a very popular engine on various platforms. In 2018 support for the 7-men Syzygy was added, shortly after becoming available. The Syzygy tablebase support, previously available in a fork maintained by Ronald de Man, was integrated into Stockfish in 2014. Stockfish supports Chess960, which is one feature that was inherited from Glaurung. As of July 2022, Stockfish 15 (4-threaded) achieves an Elo rating of 3540 +16 Compared to other engines, it is characterized by its great search depth, due in part to more aggressive pruning, and late move reductions. Stockfish implements an advanced alpha–beta search and uses bitboards. The maximal size of its transposition table is 32 TB. Stockfish can use up to 512 CPU threads in multiprocessor systems. It is derived from Glaurung, an open-source engine by Tord Romstad released in 2004. Stockfish is developed by Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad, Stéphane Nicolet, Stefan Geschwentner, and Joost VandeVondele, with many contributions from a community of open-source developers. It has won the Top Chess Engine Championship 12 times. Stockfish is consistently ranked first or near the top of most chess-engine rating lists and is the strongest CPU chess engine in the world.
It can be used in chess software through the Universal Chess Interface. Stockfish is a free and open-source chess engine, available for various desktop and mobile platforms.