3D Engine c++
Emgu CV is a cross platform .Net wrapper for OpenCV
Legion OS unofficial builds for YSL
Vivid Engine 2 is an open source 3D Engine coded using C# and C++.
3D .NET engine for Windows, Linux, Mac
A cross-platform game framework based on OpenGL and GObject.
Business graphics diagramming application + customizable shape lib.
Generates 2D layouts based on tree structures
1st 3D game engine built in C# for .NET, Visual3D Engine's predecessor