This is a "3D Game Engine" that I worked on for a third year project in university during my winter 2010 term. It isn't very functional, and the code is based off of a really terrible code base that we were required to use. I ended up spending most of my time just trying to fix it and make it work, since it only compiled in Visual Studio 6 in debug mode. It was quite a disaster to say the least, but I managed to add a few interesting things to it, like PhysX integration, shader support, heightmap based terrain generation and such.
Download: 3D Game Engine