Arianne is an engine to develop multiplayer online games like Stendhal
JavaScript framework to build game engines, games, emulators and apps
Create symmetric sprites: browse, save to PC, or store online
Free strategy browsergame engine.
Modular Gaming Open Source Persistent Browser Based Game Framework
3D Interactive sandbox environment
AMOS BASIC reimplementation in Java
Atlarius is no longer under development.
Andruill Engine is a GMS (Game Management System) written in PHP.