The original source code of the Muddle (aka MDL) interpreter has been found and is running on its original home: The Incompatible Timesharing System (aka ITS) on an emulated PDP-10. This is part of an larger overall project to resurrect ITS.
Muddle itself is a general-purpose language and isn’t directly tied to interactive fiction but it’s probably most well known for its use at Infocom.
–Dave Lebling, Classic Game Postmortem: Infocom’s Zork youtube.com/watch?v=FXdmo2j_CiQ
its.victor.se/pipermail/its-hack … 00236.html
It’s version 56/106 which is newer than the available documentation which covers 55 (ITS version) and 105 (Tenex and Tops-20 versions). Previously, people had thought version 105 was the last mainframe version (before people began porting Muddle to other systems like Apollo Domain workstations, VAX, and UNIX) but it would appear not.
To quote from the announcement:
The people seem to mostly hang out in #pdp-10 in irc.freenode.net but there is, of course, that mailing list.
I can imagine that not everyone will necessarily want to run an ancient operating system on an emulated computer (unless they happen to have a real PDP-10 just laying around somewhere) so there is also an unrelated project to bring Muddle to modern systems, via muddlers.org.