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
License: Open Source
Processing is a versatile platform primarily aimed at visual arts and interactive graphics, with strong community support and rich libraries, while Nodebox focuses on 2D graphics and data visualization, offering a simpler interface and Python integration.