3D Game engine
A basic 3D environment with a first-person POV
Modular Gaming Open Source Persistent Browser Based Game Framework
A world editor for HGE game engine written in python and uses OpenGL.
3D Interactive sandbox environment
GameWizzard is a Sprite editor.
A lightweight HTML5 Game Engine
Simple and scalable 3d javascript game engine
An extensible development framework for roleplay games.
Powerful html5 & javascript library for creating applications & games.
Formerly CraveJs, it's for creating JavaScript applications and games.
Delphi-like IDE for cross-platform game development
AMOS BASIC reimplementation in Java
DREAM is an Open Source GCS
Zap Engine