Knights Chess Interface
- Knights is a relatively new graphical chess interface for KDE. It is, however, already quite featureful and very nice looking. Doubles as a chess engine front end. GPL, Unix (KDE) only.
- http://knights.sourceforge.net/intro.php

JavaBoard for FICS
- A Java Applet allowing to play on the Free Internet Chess Server. Not very featureful, but gets the job done if you can't install an interface. Freeware, Platform independent.
- http://www.freechess.org/javaboard/index.html

ICC Interfaces
- A thorough collection of Java, Windows, Macintosh and UNIX clients which will work correctly with the ICC chess server.
- http://www.chessclub.com/interface/

Eboard
- An interface for FICS. Quite featureful. GPL, Unix/Linux only.
- http://eboard.sourceforge.net/