Panda3D is a game engine, a framework for 3D rendering and game development for Python and C++ programs. Panda3D is Open Source and free for any purpose, including commercial ventures, thanks to its liberal license. Go ahead and grab it here. To learn more about Panda3D's capabilities, visit the gallery and the feature list. To learn how to use Panda3D, check the documentation resources. If you get stuck, ask for help on the forums, our community is very active.
The latest unstable, experimental release. Includes everything you need to get started with Panda3D: the engine, the python libraries, tons of utilities, sample artwork, exporters for Max and Maya, and a copy of Python.