Cocos simplifies game creation and distribution with Cocos Creator
scene-oriented, flexible 3D engine (C++, Python, C#, Java)
Children's learning programming language Karel the Robot in 3D
A multiplatform Dart movie app with 40% of code sharing
Open-DIS implements the IEEE DIS protocol in multiple languages.
Open-source, cross-platform, C++ game engine for creating 2D/3D games
Hungry Hero is an open source Flash game built on Starling Framework.