I’m curious why they chose MDL rather than Lisp for it. Sure, it would have been ancient MACLISP or whatever, but why not leverage what was already in wide use at MIT at the time?

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WorldMaker 4 hours ago | parent | next [-]

MDL is what was in wide use at MIT at the time, the PDP-10 era. The M in MDL is sometimes "MIT" in the various backronyms of what it stood for. (Mostly it was apparently just short for "muddle", a self-deprecating description.)

(Also, to be technically correct, these source files aren't even MDL, they are a further descendant called ZIL [Zork Implementation Language].)

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staplung 5 hours ago | parent | prev | next [-]

MDL is also from MIT and supposedly stood for More Datatypes than Lisp. According to wikipedia "MDL provides several enhancements to classic Lisp. It supports several built-in data types, including lists, strings and arrays, and user-defined data types. It offers multithreaded expression evaluation and coroutines."

Seems that most of it's novelties were eventually added into LISP proper.

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jjtheblunt 6 hours ago | parent | prev [-]

maybe they just made a mini-lisp and called it MDL?

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drob518 5 hours ago | parent [-]

It’s very Lispy, but it’s not strictly Lisp. Why, for instance, use “<“ and “>” to surround various forms but not others? If they were to make a mini-Lisp, I’d expect something more like Gnu Emacs Lisp, something that’s obviously a Lisp, but heavily influenced by the Lisps of the day. I’ve found a few old MDL manuals linked from Wikipedia, but none of them have any sort of “Here’s why we created MDL” section that I could find.

	▲	DonHopkins 3 hours ago \| parent [-]
		MDL is Grue Emacs Lisp ;)