Bullet Physics is a professional free 3D Game Multiphysics Library.
Soya3D is an object oriented "high level" 3D engine for Python
Pysoy is a multi-threaded 3d game engine for Python. It's object-oriented API is designed for rapid game development while speed critical functions, such as physics processing and rendering, are implemented in C.
Cal3D is a skeletal based 3d character animation library written in C++ in a platform-/graphic API-independent way.