The Irrlicht Engine is a high performance real-time 3D engine written and usable in C++, and also available for .NET languages. It is completely cross-platform, using D3D, OpenGL, and its own software renderer.
Information regarding Project Releases and Project Resources. Note that the information here is a quote from Freecode.com page, and the downloads themselves may not be hosted on OSDN.
This is a maintenance release to the 1.5 branch of the Irrlicht engine and contains several updates and bugfixes related to terrain smoothing, joystick support, OS/XCode updates, and MS3D loader fixes.