SpirographX for Mac

From Futrell Software:

SpirographX is used to generate cool, radial images. It works like a spirograph, but with limitless possibilities. Add more loops, tweak loop diameters, and set colors to create endless visuals. The animate feature will even let you animate them in real-time.

SpirographX also includes a screen saver module which allows you to watch the visuals hands free! The module generates imagery randomly, but has detail and interval options.