| Developer(s) | Tord Romstad Joona Kiiski Marco Costalba |
|---|---|
| Stable release | 2.2 / December 29, 2011 |
| Written in | C++ |
| Operating system | Microsoft Windows Mac OS X Linux iOS |
| Type | Chess engine |
| License | GNU GPL |
| Website | www.stockfishchess.com |
Stockfish is an open source chess engine, developed by Tord Romstad, Joona Kiiski and Marco Costalba and licensed under the GNU General Public License version 3. The current version 2.1.1 (as of May 8, 2011) is available as C++ source code, and also has precompiled versions for Microsoft Windows, Mac OS X Snow Leopard, and Linux 32-bit/64-bit. The program uses the UCI protocol and can therefore be operated under various graphical interfaces. It can use up to thirty-two CPU cores in multiprocessor systems.[1] The maximum size of the transposition tables is eight gigabytes. Stockfish implements an advanced alpha-beta search and uses bitboards.
In various computer chess rankings Stockfish 2.1.1 is second or third behind the top gratis program Houdini and the commercial program Rybka.[2][3][4]
The program originated from another open source program by Romstad named Glaurung. Stockfish was forked from the 2.1 version of Glaurung; the latest Glaurung version 2.2 was released December 2008 but is no longer developed.