First Internet Backgammon Server (FIBS)
The longest running server and a popular site. A rating system ranks players according to their performance. Hosts regular tournaments.

Gammon Empire
A central repository for backgammon related information, and Patti's personal playground.

Ed's Backgammon Page
Ed's come-from-behind victory, lessons on bearing off and computing probabilities, Oregon's court ruling about backgammon, charts of dice-roll probabilities, and an entertaining collection of problems.