This is a fair question.
Lisp (List Processing Language) is as old as Fortran.
The Lisp we mean here is AutoLisp, one dialect of Lisp, the scripting language autocad chose, back in early 80s, to automate repetitive tasks within drawings, to add user commands.
It is not unlike other scripting languages (VB, Java). Easy to write and run, being interpreted by Acad.
With Acad14, it became Visual Lisp (before which we used to write it in text editor - no colors etc.)
With Acad2000, Visual Lisp became part of standard Acad.
type on Acad command line: VLIDE
and the development environment opens - with a nice Help to Autolisp in the menu.
