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.