Project MAC Progress Report IV: July 1966 to July 1967 עמוד 19:
"The higher-level language used for most of the vision laboratory program is the PDP-6 LISP System. This system is based chiefly on the LISP 1.5 programming language, but has been extensively modified in a number of ways. These include many new functions and services, including facilities for linking with programs written in other languages."
