YAML

One of my goals was to have zero dependencies -- where all you would need is a recent released of Python to run the MUD.

I think I'm going to add one though - PyYAML. Because of how I'm doing object properties, I need to let designers script events for rooms, objects, and monsters. Which means a lot of text editing. Early on, I was considering XML for this, but it's a painful format to edit manually. YAML on the other hand, is a very tight, clean format meant for straight editing.