I'm reposting a little OpenGL program I made years ago, along with some images it can generate. Sierpinksi gasket:

Sierpinski Gasket (click to enlarge)

Sierpinksi carpet:

Sierpinski Carpet (click to enlarge)

Large sample of L-Systems inspired by Lindenmayer’s book:

L-System Mosaic (click to enlarge)

I think I originally wrote this for fun, but I ended up using it for an undergraduate computer science presentation. In any case, interested parties can download the source for their own experimentation / amusement.

The project uses the GNU Autotools as a build system, so building should work with ./configure ; make.