So basically...no, it doesn't really exist. There are some things that can sort of mimic the variables using mathematics but you still have to have a brain behind it so that it makes sense. Even then we are always catching one another doing things that don't happen in nature. (See 'River Police' )

Check out some of the items mentioned above for those generators.

While GP's post seems a bit of tough love he also makes some valid points. I think a majority of us here are basically artists who make maps. Some use a lot of math and others just go with what their gut tells them. A few here have actual jobs making maps in the real world. As for me, I'm an artist who's day job just doesn't have anything to do with art. This is probably where a lot of us come from.

The reason I mention all this is so you might understand how the question raised might come across.

If I had to boil it down it would go something like this:

Hey all you artists, I would like to know if you know of a robot that can replace all of you because I am not an artist, don't have time to learn how to be one, and yet I want some art.

If there was such a robot I'm not sure how most of us would feel about it, LOL. I imagine the day a computer can paint stuff better than I can is the day I'm hanging up my crayons.