The inspiration for cf3ruby is contextfreeart and the jashkenas original, so what is context free art?

Chris Coyne created a small language for design grammars called CFDG. These grammars are sets of non-deterministic rules to produce images. The images are surprisingly beautiful, often from very simple grammars. In the original version there were 3 terminals of a TRIANGLE, SQUARE and CIRCLE see cfdg how_to.