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.js is primarily focused on web integration and is easier for beginners to create interactive content, while Processing offers more advanced features for complex graphics and 3D. Processing is better for traditional programming environments, whereas Processing.js excels in web-based applications.