While TurtleToy is way more advanced, few years ago I built a small webapp that uses nested CSS to make recursive images: https://zetabee.com/weave/
Click [Help] button to get an idea of how it works. It was heavily inspired by Structure Synth but written from scratch to work with CSS3 in a modern browser.
Click [Help] button to get an idea of how it works. It was heavily inspired by Structure Synth but written from scratch to work with CSS3 in a modern browser.