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
Apps available for
Mac OS X
Processing is an Open Source Product.
Casey Reas, Ben Fry, and many others: http://www.processing.org/about/people.html has developed Processing