NodeBox family of tools gives you the leverage to create generative design the way you want.
Developed by Experimental Media Group
License:Open Source
Apps available for
Mac OS X
Windows
Linux
VS
VS
Processing
Processing is a flexible software sketchbook and a language for learning how to code within the context of the visual arts.
Developed by Casey Reas, Ben Fry, and many others: http://www.processing.org/about/people.html