For GNU/Linux users: open a terminal and run
gnubg -t.
MS Windows users: Look for a file
called gnubg-cli.exe in GNU
Backgammon's install directory or open the MS Windows
menu Start->Run... and type
c:\[path-to-your-gnubg]\gnubg-cli.exe. There is
also a menu entry GNU Backgammon Command Line Interface.