Preserving code that shaped generations: Zork I, II, and III go Open Source
"Today, we’re preserving a cornerstone of gaming history that is near and dear to our hearts. Together, Microsoft’s Open Source Programs Office (OSPO), Team Xbox, and Activision are making Zork I, Zork II, and Zork III available under the MIT License. Our goal is simple: to place historically important code in the hands of students, teachers, and developers so they can study it, learn from it, and, perhaps most importantly, play it.
"...The games remain commercially available via The Zork Anthology on Good Old Games."
https://opensource.microsoft.com/blog/2025/11/20/preserving-code-that-shaped-generations-zork-i-ii-and-iii-go-open-source
https://github.com/historicalsource/zork1
And an Ars Technica article about that:
https://arstechnica.com/gaming/2025/11/microsoft-makes-zork-i-ii-and-iii-open-source-under-mit-license/
I originally beat Zork in the original PDP-10 version, arpanet-ing in to MIT to play it.
The original Zork written in the MDL dialect of Lisp was already available:
"This version of ZORK has been (slightly) changed from the original in order to run on the Confusion MDL Interpreter.
https://github.com/whitten/MDL-Zork
There's also this:
'This directory contains files related to Confusion, an MDL interpreter which, to quote its author, "Works just well enough to play the original Zork all the way through."'
http://www.ifarchive.org/indexes/if-archive/programming/mdl/interpreters/confusion/