Guix

MDL (the MIT Design Language) is a descendant of Lisp. It was originally developed in 1971 on the PDP-10 computer under the Incompatible Timesharing System (ITS) to provide high level language support for the Dynamic Modeling Group at MIT's Project MAC. Infocom built the original PDP-10 Zork in MDL and their later ZIL (Zork Implementation Language) was based on a subset of MDL. Confusion is a MDL interpreter that works just well enough to play the original mainframe Zork all the way through.