GNU Backgammon is a world class opponent and rates at over 2000 on FIBS, the First Internet Backgammon Server.
The following features can be found in the current release of GNU Backgammon.
A command line interface (with full command editing features if GNU readline is available) that lets you play matches and sessions against GNU Backgammon with a rough ASCII representation of the board on text terminals.
* Support for a GTK+ interface with a graphical board window. Both 2D and 3D graphics are available.
* Tournament match and money session cube handling and cubeful play. All governed by underlying cubeless money game based neural networks.
* Support for both 1-sided and 2-sided bearoff databases: 1-sided bearoff database for 15 checkers on the first 6 points and optional 2-sided database kept in memory. Optional larger 1-sided and 2-sided databases stored on disk.
* Automated rollouts of positions, with lookahead and variance reduction where appropriate. Rollouts may be extended.
* Automatic and manual annotation (analysis and commentary) of games and matches.
* Record keeping of statistics of players in games and matches (both native inside GNU Backgammon and externally using relational databases and Python).
* Loading and saving analyzed games and matches as .sgf files (Smart Game Format).
* Exporting positions, games and matches to: (.eps) Encapsulated Postscript, (.gam) Jellyfish Game, (.html) HTML, (.mat) Jellyfish Match, (.pdf) PDF, (.png) Portable Network Graphics, (.pos) Jellyfish Position, (.ps) PostScript, (.sgf) GNU Backgammon File, (.tex) LaTeX, (.txt) Plain Text, (.txt) Snowie Text
* Import of matches and positions from a number of file formats: (.bgf) BGRoom Game, (.gam) GammonEmpire Game, (.gam) PartyGammon Game, (.mat) Jellyfish Match, (.pos) Jellyfish Position, (.sgf) GNU Backgammon File, (.sgg) GridGammon Save Game, (.tmg) TrueMoneyGames, (.txt) Snowie Text
* Python Scripting ability.
* Native language support; 15 languages complete or in progress: (cs_CZ, da_DK, en_GB; en_US, fi_FI, fr_FR, de_DE, el_GR, is_IS, it_IT, ja_JP, ro_RO, ru_RU, es_ES and tr_TR)