VPython and Glowscript
First, there is VPython (http://www.vpython.org). This is a free module for python so you can do some cool 3D calculations and animations.
Next – Glowscript (http://www.glowscript.org/). Essentially the same idea as vpython, but it runs in most browsers.
Oh, you want to use vpython in the computer lab? Oh, they don’t have it installed? Here, Sean fixed your problem. First you can download this USB-driveable version of vpython:
Now watch Sean’s tutorial.