Game Development

Arianne
Arianne is a multiplayer online games framework and engine to develop turn based and real time games.
http://arianne.sourceforge.net

Glutamine: The Game Tool Chest
C library for networked, 3D interactive applications. Documentation, related projects, source, and binaries.
http://gtc.seul.org/

Linux Game Development Center
Resources for game development on Linux, FreeBSD, and other open platforms.
http://lgdc.sunsite.dk

Simple DirectMedia Layer
A cross-platform multimedia library designed to provide fast hardware access.
http://www.libsdl.org