A 'Fault Line' Fractal Terrain Generator.
Outputs heightmaps as greyscale TGA images.
The code I used to render the terrain in 3D is long gone but it should be easy enough to tri-strip from the image data if you want to.
There is the option to use the 'Logistic Function' instead of rand() for placing fault lines. If you do, and run for enough generations, you will get some beautiful swirls in the terrain. The function appears 'chaotic' when considered in one dimension, but in higher dimensions, fractal properties emerge.. as I remember, it can be fun to play with.
This is very old code, but if you want the generator, it should be easy enough to extract..