2D JavaScript Physics Engine
A 2D rigid body physics engine for the web
Amazon Lumberyard is a free AAA game engine
3D .NET engine for Windows, Linux, Mac
Articulated-body simulation engine written in C
simulations with Lagrangian method,both symbolic and by numeric deriv
Pear3DEngine is a modern and modular 3D development framework
1st 3D game engine built in C# for .NET, Visual3D Engine's predecessor