Children's learning programming language Karel the Robot in 3D
Build Cross-platform Applications
Multi-threaded game engine for Android
A VR puzzle game for Cardboard using Unity
RelaxChess, chess game that makes no search futher needed for a wow
The Atomic Game Engine is a multi-platform 2D and 3D engine
online 4X browser game engine
Modern AS3 Game Engine
3D .NET engine for Windows, Linux, Mac
Open-source, cross-platform, C++ game engine for creating 2D/3D games
Dragging and Dropping Components for Multi-projection Applications
Cross platform 2D/3D game engine written in C++11 & OpenGL ES 2/3
Egret is a brand new open mobile game and application engine
2D physics engine for games
Visual Novel engine, editor and game development.
A free open source Android version of Caravan
An Open Engine for use on the OUYA
C-Lesh is a game programming language for 2D games.