RMS's Lisp Experiences and the Development of GNU Emacs
There's a new transcript of an RMS LISP talk up on gnu.org. Some choice tidbits:
Actually, there were some rather sophisticated facilities; I think that Lisp got its unwind-protect facility from TECO.
on EMACS LISP features:
I implemented Common Lisp once on the Lisp machine, and I'm not all that happy with it. One thing I don't like terribly much is keyword arguments. They don't seem quite Lispy to me; I'll do it sometimes but I minimize the times when I do that.