WinBoard

Chess services, including:
- Chess engines that will run on your machine and play a game against you or help you analyze, such as GNU Chess, Crafty, or many others.
- Chess servers on the Internet, where you can connect to play chess with people from all over the world, watch other users play, or just hang out and chat.
- Correspondence chess played by electronic mail.

The CMail program automates the tasks of parsing email from your opponent, playing his moves out on your board, and mailing your reply move after you've chosen it.