A dialect of Lisp developed at MIT AI Lab in 1966, known for its efficiency and programming facilities. Later used by Project MAC, Mathlab and Macsyma. Ran on the PDP-10. Introduced the LEXPR (a function with variable arity), macros, arrays, and CATCH/THROW. Was once one of two main branches of LISP (the other being Interlisp). In 1981 Common LISP was begun in an effort to combine the best features of both.

["MACLISP Reference Manual", D.A. Moon <[email protected]>, TR Project MAC, MIT 1974].