Create cool CSS background patterns for your web design work with this collection of pure CSS patterns
MagicPattern - The best design toolbox with 10+ tools for anyone
Hero Patterns - A collection of repeatable SVG background patterns
PatternPad - Create beautiful geometric patterns
Generative Art in Go - Learn the basics of algorithmic art with the Go language
The Pattern Library - Free to use patterns by awesome designers
Ramsophone - A generative art/music machine. (Be sure to refresh!)