From the Processing website:

"Processing is a flexible software sketchbook and a language for learning how to code within the context of the visual arts. Since 2001, Processing has promoted software literacy within the visual arts and visual literacy within technology. There are tens of thousands of students, artists, designers, researchers, and hobbyists who use Processing for learning and prototyping."

Try Processing online

Some of my sketches at OpenProcessing

Recursion is weird

Wacław Szpakowski

Wacław Szpakowski was an architect, engineer and a violinist, among other things. He also made amazing geometic drawings from single continuous lines:

Paris Review article

By coincidence I've been experimenting with spiral patterns in processing:


This is the same process:

Saskia's Tiles

Inspired by Saskia, coded by me