Lisp Language

There are several languages in the Lisp Language family . . .

COMMON LISP
The Common Lisp language, which has an associated ANSI standard, is generally referred to as an industrial-strength, commercial-quality standard for powerful and relatively portable applications.
ISLISP
The ISLISP language, which has an associated ISO standard, is a more minimal language, about one tenth the size of Common Lisp.
MACLISP
The MACLISP dialect ran on the DEC PDP-10 and Honeywell Multics and was popular in the 1970's and 1980's. It is now of primarily historical interest, although it continues to run on software emulations of the PDP-10, to be found scattered about the net. (There is no name relation to nor compatibility with the Macintosh, which didn't exist at the time it was in popular use.)