I use XEmacs. Many (~10) years ago I went back and forth between both and found that I really preferred XEmacs more. A lot of it went to the thought that JWZ

I use XEmacs. Many (~10) years ago I went back and forth between both and found that I really preferred XEmacs more. A lot of it went to the thought that JWZ and others put into being a proper X11 application; and the fact that it wasn't X11-only: you could have full colors in a terminal (and dark/light color theming) and they listed a packaged Win32 build on their site. Other thoughts - XEmacs at the time seemed better prepped for picking up and running with out of the box. I think the situation's probably a little reversed now; I see some nice stuff in GNU Emacs out of the box and some extensions are either GNU-only or with XEmacs as an afterthought. That said, everything I use works fine in XEmacs, and I can always hack anything I need. That brings me to my next favorite: extending the editor. GNU Emacs has inherited (apparently from RMS) a dislike for abstract data structures. Everything's a list of chars, which are just integers. You can implement other things on top, but your tools are limited and at the interface with Emacs itself it's about as low-level and manual as Unix syscalls it seems. Fontifying is also handled more cleverly in XEmacs. Some of this may have changed since I last looked into it in detail. Finally, as a Common Lisp developer, XEmacs Lisp leans more in that direction than GNU Emacs Lisp, which seems like a crufty amalgam of MacLisp and Scheme, plus the aforemention disdain for data structures. I'd probably be happier with an entire Common Lisp editor but XEmacs does so much. An anecdote: recently a friend had to use Emacs for school to work with Mozart (http://www.mozart-oz.org/ http://www.mozart-oz.org/). I actually suggested he use GNU Emacs because while I favor XEmacs I know GNU Emacs is a little more actively developed and widely used. He had a few things he wanted help customizing and I was shocked how arcane some of them were to customize in GNU Emacs (read, Lisp coding, and not clean Lisp coding either), while in XEmacs they were simple checkboxes in the "Options" menu. I forget the specific examples but I can post if I remember. I do wish XEmacs were more actively developed -- maybe that's a hint for me to jump in and start helping out -- and I especially wish the 21.5 series would hurry up and get made into a stable release version so the good new features in there would be widely available. However I still find XEmacs to be a great editor and more useful for _my_ needs than GNU Emacs.