OT: Terrain Generator

[President_Elect_Shang]

I'm looking to create a random planets surface complete with mountains, streams, valleys, and so forth. I have spent the better part of last night looking and although I have found several fractal terrain programs I can't really tell which may be the best for my purposes. I ultimately want to export the file and generate a cyberboard out of the map. However, I first need to generate the planet.

So any suggestions as to what is a good software for this?