Arianne is an engine to develop multiplayer online games like Stendhal
An open-source Phantasy Star Online server for *nix
BOT IRC in Perl
LGSL (Live Game for PHP 5.4-8+: online status for various gameservers
A fun realistic multiplayer free-and-open-source first-person-shooter!
Multidocument automation by templates - for sphinx, mkdocs, epydoc ...
Cross platform administration tool for Source Engine dedicated servers
Yet Another PHP EVE API Library.
An e-stim signal generator in java
Rigs of Rods Multiplayer server
Automatic chooser of optimal fleet (with limits) for ogame browser gam
Game framework on top of Python, Panda3D and Twisted