Vivid is a modern C++ 3D engine using OpenGL4+
Vivid Engine 2 is an open source 3D Engine coded using C# and C++.
Cross-platform 2D and 3D game engine
.NET wrapper for the Irrlicht Engine
3D game engine for C and C++
Megalui: 2D/3D OpenGL & C/C++ Library for Scientific Visualizations