This system is advertised in the comp.lang.lisp faq as available from nebula.cs.yale.edu. That host doesn't exist any more, but you can still get it from the AI Repository at CMU. (See also http://www.1729.com/plisp for another version with a few fixes.)
It's Public Domain. Although some of the source files have individual copyright messages, the author was contacted in February 2003 and said "Go nuts. Delete copyrights. Have fun."
The author is now at email@example.com - I'd be interested to hear if this software is still alive somewhere. -- John
An example from the demo/ directory -
(defun inch (x) 1 (* x 72)) (defun wedge () 0 (with-newpath (moveto 0 0) (translate 1 0) (rotate 15) (translate 0 (sin 15)) (arc 0 0 (sin 15) -90 90)) (with-gsave (translate (inch 3.75) (inch 7.25)) (scale (inch 1) (inch 1)) (wedge) (setlinewidth 0.02) (stroke)) (with-gsave (translate (inch 4.25) (inch 4.25)) (scale (inch 1.74) (inch 1.75)) (setlinewidth 0.02) (dotimes (i 12) (setgray (/ (1+ i) 12)) (with-gsave (wedge) (with-gsave (fill)) (setgray 0) (stroke)) (rotate 30))) (showpage)