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 <moon@cambridge.apple.com>, TR Project MAC, MIT 1974].