Individual posts are copyright by their authors and I claim no exclusive rights to them. Click through the posts to the parent blogs and you should be able to find terms for reproduction.
All of the software behind this site is open source. Everything I produced is available under the AGPLv3 license.
I will at some point package the source code. Right now the code has some trashy hacks and the setup is extremely ugly. But now that I have running code, I'll clean it up slowly. Please let me know about bugs. Soon the code will be available from this page. But until I get around to it, there's always GitHub:
git clone git://github.com/jvasile/Planeteria.git
Run generate.py in the root of that branch. See the readme for details.
A previous version of Planeteria was based on Venus, which I highly recommend if you are trying to run just one planet.