The original ML was implemented in Lisp (Stanford Lisp) as part of the Edinburgh LCF (Logic for Computable Functions) theorem prover. Different syntax, types -

The original ML was implemented in Lisp (Stanford Lisp) as part of the Edinburgh LCF (Logic for Computable Functions) theorem prover. Different syntax, types - but other stuff it had were easily shared in the implementation with the underlying Lisp: functions, higher-order functions, garbage collection, lists (with cons and append operators), lambda expressions, ... Here is a version of LCF with that first ML from 1977: https://github.com/theoremprover-museum/LCF77 https://github.com/theoremprover-museum/LCF77