runouw.com

Mandelbrot Sets are an interesting aspect of mathematics that I personally haven't studied much about (not formally, anyway). I suggest researching them if you want to know more about them.

Runouw programmed his own Mandelbrot Set, which I happened to find on SheezyArt a couple months back:
http://www.sheezyart.com/art/view/2390476/

The level of detail depends on the programmer, but a Mandelbrot Set is technically infinitely complex (from what I gather). I found some other great examples - and a great explanation - of Mandelbrot Sets on HTwins.net (the guys who made Scale of the Universe).

To my disappointment, there is a limit to how detailed you can zoom in. Is it even possible to make one where you can zoom in infinitely and it keeps getting more detailed? I don't know. Either way, Mandelbrot sets are cool.