HTLS is an Hattrick live match viewer, based on the old Livefox.
3D urban environment renderer : browser-app ; as well as a GTA clone
Modular Gaming Open Source Persistent Browser Based Game Framework
a PHP based leaderboard software for Battlefield 3
A Core War with time manipulation!
Earthlead is a free massive multiplayer online browser strategy game.
Game engine supporting many 3D/2D formats and graphic effects
Free MMORPG Engine. Develop and host graphical browser-based games.
Game engine and ready browser game Pulsar Online