You may find a post I wrote entertaining. It talked a bit about 'taking back protocols' a few years ago.

Sorry for any broken links, I abandoned blogging due to toxic commenters.

http://cowbelljs.blogspot.ca/2011/12/lost-art-of-telnet.html...

You reminded me with your talk of MUDs of the growing IF (interactive fiction) movement. It's not multi-user, but it has a lot of the feel of those old text adventures. If that's interesting to you, I'd recommend trying out Blue Lacuna - http://blue-lacuna.textories.com/