Popular in the 20th century, MUDs are text-baased Multi-player games, similar to our modern day MMOs.
Gladiator Pits, of which this source code is the only public version (to my knowledge) still available, is a excellent example of a MUD, clearly commented, with precision and intuitivity.
Richard Woolcock wrote in
This code is copyrighted to me, however you're welcome to use it for anything you wish, so long as you don't remove the copyright notices from any source files containing any of the mud source code.
And therefore, the most applicable license appears to be the MIT license.
I in no way claim authorship, nor authority, over this excellent piece of code, but release it, under its author's original terms and conditions, to the general public.