I’ve been an Emacs hacker off and on for almost 30 years (yes, I first played with it when it was in Teco). I’ve never really written any Emacs Lisp (or Teco) – I’ve just hacked together pieces of code that I found in various places (like the various Emacs newsgroups). Lately, though, it seems that Emacs is changing so fast that I can’t keep up with it anymore.
I’ve used Emacs. I’ve used XEmacs.