When I started writing in 1993, and had not decided whether I wanted to write science fiction or Romance, I heard of a program called Kepler. As I recall, one was supposed to be able to design alien worlds and check them out.
I never found it.
However, this week I found codecademy. One of the starter lesson sets allows the rookie coder to try world-building.
Look for it here: http://www.codecademy.com/learn
For one reason or another (unless you are already tech savvy) you might be glad you gave it a try. I am.
My apologies for an ultra short blog. I'm preparing for a discussion of the DMCA for the USPTO, with especial emphasis on the benefits of standardizing Take Down notices.