GNU Backgammon (gnubg) is for playing and analysing backgammon
positions, games and matches. It's based on a neural
network. Though it already plays on a very high level, it's still
work in progress. You may play GNU Backgammon using the command
line or a graphical interface (based on GTK+).

WWW: http://www.gnu.org/software/gnubg/gnubg.html