Check out 'Elevated' - winner of the 4k PC demo category at Breakpoint 2009. It's a fly-through of a realistic looking procedurally generated terrain model with music and some fancy post processing effects all squeezed into a <4096 bytes executable. Even my moderately high-end PC can't run it (I suspect because it shoves an overwhelmingly huge triangle mesh at the GPU) but there's a video here:<p><a href="http://www.youtube.com/watch?v=_YWMGuh15nE" rel="nofollow">http://www.youtube.com/watch?v=_YWMGuh15nE</a>
The article is mostly about <i>rendering</i> terrain, not generating it, and it also has nothing to do with reddit.<p>However, the rendered results do look relatively nice, and the article (even as awfully paginated as it is) gives a pretty good idea on how to get there from zero.
With all due respect, <i>this</i> is not awesome. Nowhere near it.<p>But this - <a href="http://www.planetside.co.uk/terragen" rel="nofollow">http://www.planetside.co.uk/terragen</a> - is.