This looks pretty cool, Perlin noise is used all over the place in procedural content generation. I recall Minecraft's terrain is generated using it.

I have no idea why the author didn't include a usable demo though. It would be nice to try out the texture generation without copy-and-pasting, saving and running the code.

Threw it up at http://www.simcop2387.info/texture.html since there isn't a demo that I found on that page. Seems to be a bit slow but interesting idea still.