It's licenced under the GNU General Public Licence, version 2, or at your option any later version. Note: we do not consider a game world written for musicmud, or code written in lua to interface with it, a derivative work of musicmud.
Download 2.1.6b here
Some very patchy getting started docs
Building Tutorial (being written)
Testing and other help by Andrew Anderson, Ian Dundore, Graham Evans, Caroline Ford, Daniel Hunter, Martin Lester, Tim Ridgen, Samantha Thomas, and Alex Turner.