Glenn Burke; David Moon; MASSACHUSETTS INST OF TECH CAMBRIDGE LAB FOR COMPUTER SCIENCE.
LOOP is a Lisp macro which provides a programmable iteration facility. The same LOOP module operates compatibly in both Lisp Machine Lisp and Maclisp (PDP-10 and Multics). LOOP was inspired by the 'FOR' facility of CLISP in InterLisp; however, it is not compatible and differs in several details. (Author).