GNU Backgammon (gnubg) is for playing and analysing backgammon positions,
games and matches. It's based on a neural network. In the past twelve months
it has made enormous progress. It currently plays at about the level of a
championship flight tournament player. Depending on its parameters and its
luck in recent games, it rates from around 1900 to 2000 on FIBS, the First
Internet Backgammon Server -- at its strongest, it ranks in the top 5 of over
6000 rated players there) and is gradually improving; it should be somewhat
stronger than this when released. Since almost all of the CPU time required
during supervised training is spent performing rollouts, and rollouts can
easily be performed in parallel, it is hoped that users will be able to pool
rollout results and collectively train it to a level stronger than any
individual could obtain.

You can also compete against recent versions of gnubg on FIBS; it plays
there under the names gnu, mgnutest, mpgnu, mgnu_advanced, mgnu_expert,
mgnu_WClass, ParlorBot and mgnu_zp.

GNU Backgammon also playes on GamesGrid. A version of GNU Backgammon with no
lookahead, 0-ply, plays with the nickname GGraccoon. GGraccoon is a very
popular opponent among the members at GamesGrid. GGraccoon usually rates
about 1900.

You may play GNU Backgammon using the command line or a graphical interface
(based on GTK+). For 3D Boards support you will need the GTK OpenGL
extension (gtkglext) available at SlackBuilds.org.