Arianne is an engine to develop multiplayer online games like Stendhal
GameServer is a sophisticated, game server designed for online games
A fun realistic multiplayer free-and-open-source first-person-shooter!
LGSL (Live Game for PHP 5.4-8+: online status for various gameservers
oGame-like browser space realtime strategy game based on xNova
online 4X browser game engine
Alpha One is based on Vallheru
Game engine allows you to create own MMORPG
Evidyon - No Man's Land FREE Open Source MMORPG
MuIsrael game client
Modular Gaming Open Source Persistent Browser Based Game Framework
Minecraft private Skin Center
Brutal Is An SQL C# Random Gen Game.
A MMORPG Engine, written in PhP and SQL
Mafia MMORPG Browser-Based game
Hra piškvorky - Game gomoku
A multiplayer Blackjack game which works over the internet