For Casey Reas, software is the most natural medium to work with. He uses code to express his thoughts—starting with a sketch, composing it in code, and witnessing the imagery that it ultimately creates. We visit his studio to see how he uses color to convey emotion and how his programming language Processing is closing the gap between software and object.
From creating maps, to languagues, to dungeons or artwork, this list has lots of generative tools to help you.
There are end-user tools, code frameworks, free tools, paid tools and lots I'd never heard of.