Ah, Autolisp. Based on an early, early version of XLisp, it's zombie software: not quite alive—Autodesk really wants you to use its COM and .NET integration to program AutoCAD—nor can it truly die. It was also the first Lisp I ever programmed, and back in the mid-90s there was a trend of putting a Lisp, or Tcl, into all the things (Emacs, GIMP, frickin' Abuse...) and Autolisp had prepared me for that world rather well.