That's pretty comprehensive, but this is the best introduction to Bezier curves I've ever seen: http://en.wikipedia.org/wiki/File:Bezier_2_big.gif

The article has very good illustrations, I am wondering what was the software used.

MetaPost would be the usual suspect, but he probably used his own Python-to-PostScript wrapper: http://www.math.ubc.ca/~cass/piscript/docs/piscript.html .

Recently many mathematicians I know are plotting with NodeBox which is a VJ software akin to Proce55ing but using Python.

Edit: He also authored a lovely PostScript cook book http://www.math.ubc.ca/~cass/graphics/manual/

thanks, great info. P.S. AFAIK Processing is not 55 anymore