Arianne is an engine to develop multiplayer online games like Stendhal
JavaScript framework to build game engines, games, emulators and apps
Game engine supporting many 3D/2D formats and graphic effects
Java Settlers
The imaginary eight-bit machine
A complete web framework to create online Fighting Fantasy adventures
3D .NET engine for Windows, Linux, Mac
Create symmetric sprites: browse, save to PC, or store online
Free strategy browsergame engine.
AutoTeach makes kids study and learn in exchange for internet access.
Modular Gaming Open Source Persistent Browser Based Game Framework
Open source network game service
C-Lesh is a game programming language for 2D games.
An HTML web game platform
Simple Point & Click Game
Atlarius is no longer under development.