I knew that Infocom’s ZIL was based on MDL, which was based on Lisp. What I didn’t know until this week is that ZIL doesn’t have lists. Lisp without lists!

The reason being that Zork was supposed to be a quick hack to make some money while Infocom built their actual product, and they already had Zork written in MDL at MIT. So it was a case of implementing the least MDL possible with the smallest runtime possible so they could port Zork to popular home computers.

Anyway, an article by @zarfeblong will tell you a lot more about ZIL if you’re interested:

https://blog.zarfhome.com/2019/04/what-is-zil-anyway.html #InteractiveFiction