This is an unusually easy-to-use module for Python that generates navigable 3D animations as a side effect of computations. See vpython.org for current stable downloads and much other information. As of 2012 April 10, source code updates take place at github.com/vpython.
Valuable software allows rapid development of 3D applications in Python.
As you know, "3D" is synonymous with "Extremely Hard". Leave it to a programmer to call this a 3D library.
Super easy to use. And of such educational value! I think it comes from the fact, that to really understand a physical situation, you have to look at it from all sides. That's where VPython comes in very handy. Understanding nature IS understanding it in 3D.