The source code to VVVVVV
Multi-platform 2D and 3D game engine
Orx: Data-Driven Game Engine
GLScene Engine for Delphi & C++Builder VCL Windows 32/64
... the open-source glide computer
GEDKeeper - opensource and crossplatform genealogy management program
Reactive extensions for Unity
3D .NET engine for Windows, Linux, Mac
Dragging and Dropping Components for Multi-projection Applications
PixelLight is a cross-platform application framework
Cross-platform 2D game engine
A Multimodal approach to control a Unmanned Aerial Vehicle