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 http://

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 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/ http://www.math.ubc.ca/~cass/graphics/manual/