I uploaded a new version to Steam which allows you to create your own custom maps. You can create in a paint program a heightmap and then use it to create a Synthetic World map. You can also define the vegetation level and the climate zones. 2 example maps are included. Have fun:

click to go to youtube

1 pixel = 1 meter
The heightmap start at 64 m above the map ground and ends at 196 m. The water level is at 96 m above the ground. So the water plan equals in the height map the color (64,64,64) if (255,255,255) is white in your paint program (this is the case with Gimp). If (100,100,100) is white (like it is for example with Corel Draw the case) then (25,25,25) would be the water level. The height map is smoothed when loaded into the game.

Here is the example map which is included:
Heightmap:

Climazone (everywhere the same):

Vegetation Level:

And we also increased the speed of the world generator. And we also worked on computer generated houses and cities.