Ethereum .Net cross platform integration library
Modern 3D engine and IDE written using C# and C++.
Vivid Engine 2 is an open source 3D Engine coded using C# and C++.
WebCam Eye Tracking for usability testing
3D Evolutionary Tree Visualization
3D .NET engine for Windows, Linux, Mac
An expanded XNA game creation framework
XNA based game engine completely written in c#
Azmyth Game Framework
Easy Terrain editing and Heightmap creation
https://github.com/horde3d/Horde3D
1st 3D game engine built in C# for .NET, Visual3D Engine's predecessor
SmartMap is an easy desktop random world creator.