Developer(s)The PyChess Project
Initial release13 September 2006; 17 years ago (2006-09-13)
Stable release
1.0.3 / 19 March 2021; 3 years ago (2021-03-19)
Written inPython (PyGTK)
Operating systemUnix-like, Windows
Available in61 languages[1]
TypeComputer chess
LicenseGNU General Public License 3

PyChess is a free software chess client developed for GNU. It allows users to play offline or online via the Free Internet Chess Server (FICS). PyChess also incorporates a built-in chess engine, which in contrast to most other chess AIs is written in the Python language and focuses more on fun of play than raw strength. For more advanced users, PyChess allows for virtually any other external chess engine to be used with it.[2]


Development on PyChess was started by Thomas Dybdahl Ahle in 2006, and the first public release was sent out later that year.[3] The release contained the bare minimum of features to play a game of chess, and was backed only by the GNU Chess engine.

In the end of 2006, PyChess was close to become a part of GNOME Games, which were holding a usage survey of aspiring new games to include in the suite.[4] Being nearly just started at the time, it lost to the more established glChess, which managed to fix its hardware accelerating dependency before the end of the trial.[4][5] glChess is still developed as a part of GNOME today. Afterwards there were talks of the two programs merging, but the developers decided they were targeting different user segments, with PyChess aiming towards more advanced users.[6]

In 2009 PyChess won Les Trophées du Libre in Paris in the category of hobby computing.[7]

PyChess has grown steadily since then, with increasing year-to-year development activity, and would cost more than $500,000 to develop today in terms of the man-hours required to develop such a codebase.[8] By 2011 it was among the seven most frequently used chess clients to access the Free Internet Chess Server,[9] which in turn is the only non-web-based chess server available for Linux.

Version 0.12 of PyChess uses PyGObject and GTK+ 3, prior versions used the obsoleted PyGTK.[10]


According to the PyChess website:

The goal of PyChess is to provide an advanced chess client for Linux, and do that with a nice and efficient user interface in line with the GNOME Human Interface Guidelines. The client should be fun and exciting to those new to chess – who just want to play a short games to procrastinate their work – as well as those who want to utilize their computer for further enhancing their play.[13]

The PyChess project puts heavy emphasis on simplicity, trying to avoid the complicated user interfaces of XBoard and BabasChess. This implies adding new features slowly, so they can be integrated in the overall usage scheme, and make things "just work". At the same time the project strives to contain most of the features known from major Windows chess clients such as Chessbase and Aquarium by ChessOK.

See also


  1. ^ "pychess/lang". Github. Archived from the original on 1 August 2021. Retrieved 25 August 2021. 61 files for languages can be counted, excluding one other file (pychess.pot).
  2. ^ "About PyChess". Retrieved 25 August 2021.
  3. ^ "Pychess 0.2". 13 September 2006.
  4. ^ a b "GNOME Games Plan for Included Games". 3 September 2006. Archived from the original on 3 September 2006.((cite web)): CS1 maint: unfit URL (link)
  5. ^ Ancell, Robert (15 September 2006). "glChess... Now in 2D!".
  6. ^ Ancell, Robert (17 December 2006). "Summary of current open-source chess programs".
  7. ^ Kehrer, Anika (9 June 2009). "Die kleine große Freiheit". Linux Magazin (in German). Linux New Media AG. Archived from the original on 31 December 2016. Retrieved 17 July 2011.
  8. ^ "PyChess at Ohloh". 9 July 2011.
  9. ^ "PyChess News". Archived from the original on 30 December 2016. Retrieved 10 July 2011.
  10. ^ "PyChess 0.12 in Debian 9 repository".
  11. ^ Kreński, Karol. "Issue 160 – Alternative Logo". Retrieved 25 March 2007.
  12. ^ Kreński, Karol. "Galeria Karola Kreńskiego". Archived from the original on 31 December 2016. Retrieved 10 July 2011.
  13. ^ "PyChess at GiHub Project Hosting". GitHub. Retrieved 10 July 2011.

Media related to PyChess at Wikimedia Commons