This is a map generator based on Voronoi diagrams.
Currently, only the elevation generation works, but additional functionality such as erosion, hydrological simulation, and weather simulation is intended. The elevation generation is based on a very simple and heavily fudged simulation of plate tectonic activity.
I use a modified version of PouletFrit's csDelaunay library. You should be able to drop the library straight into the Assets directory and then incorporate both into your project.