Uncharted Atlas

I discovered a new website that is doing random maps. The highlight is a twitter channel that has a new map every hour. And I must say, they look very nice. Martin O’Leary has even given the source code for his algorithms. I am now going to have to go through them and discover what he is doing.
It has already given me some ideas. In my maps, I use a grid for everything. He is using polygons. I can see advantages of both methods. I’ve been having some doubts about my grid system, but I’m thinking of a combination of the two.
With 3D graphics and video cards these days, I am probably not shackled to the tyranny of the grid anymore.
Martin is doing a good job of generating rivers and I want to look at how he is doing water flow. I’ve been planning a good method, but a brief look over his tutorial, and I find he is dropping the names of some algorithms I should know more about.
My biggest issue with his maps is that he treats sea level as the end result. Look at this:

There is a big lake, but it doesn’t have an outflow to the ocean. He is probably stopping all water flow as soon as it hits sea level. And that helps with quickly generating everything. But in reality there are freshwater lakes that have a depth that puts their bottoms below sea level. Those lakes still have outflows to the ocean, but their surface is well above sea level.

Actually, looking at his maps, there are no lakes at all. This is the closest:

They still feel like they are just another set of sea level lakes.