I have released my learning tool, MakeBot, as open-source software. There is a new website: stratotools.python-hosting.com which holds all the source-code for the tools developed here. The latest addition is MoonUnit, a 3D graphics library. It’s under development for courses I will give this summer. So far you can draw spheres, boxes, cylinders and cones in 3D. You can also load .3DS format models into your scene.