catflap.org Online Dictionary Query

  MacLisp
       
          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
          , TR Project MAC, MIT 1974].