Software

Bgblitz
Professional Backgammon Software for Windows, Mac and Linux.
http://www.bgblitz.com/

3DFiBs
Built on the GNUBG engine and allows for online play at First Internet Backgammon Server. Contains downloads, screenshots, support, and common terms. Available for Windows.
http://download-texas-holdem-poker.com/backgammon/backgammon.html

GAMMONLAB
Freeware program for playing practice games and matches. Offers match analysis and position evaluation.
http://www.gammonlab.com

JellyFish
A neural net based program that plays at a very high level.
http://effect.webbie.net/jelly.htm

MaxGammon
Shareware program with 3D color, adjustable skins, strong AI, network capability and multi-language support.
http://www.stronggames.com/maxgammon

MVP Backgammon Professional
Shareware program for windows with three skill levels and free online play.
http://www2.mvpsoft.com/games/product.xml?product=MvpBackgammon

Romar Backgammon
Freeware program to play against the computer, or against a friend online.
http://home.hccnet.nl/r.marseille/backgeng.html

Snowie Professional
Tool that allows analysis of matches with a user-friendly interface and neural net based logic.
http://www.bgsnowie.com/