azoth engine (free - MIT - messy!)
 

Hiya! I'll keep this short..

I was going to make a mud, but then I didn't. I learned lua and programming by writing the engine, so.. it's a damn mess. I cleaned it out some and dumped it on github. All I ask if you do use it is a.. shout out or something.

You can get it , but if someone forks and improves it I strongly advise you use their version instead. It's mostly crash resistant and should reload most code changes without needing to terminate the main loop.

EDIT:
I cleaned it up a bit more after learning that github isn't such a scary thing after all. :)