I use GNU Emacs, mostly on GNU/Linux (Debian and Red Hat).
I’ve tried XEmacs, but something about it puts me off. I’ve never quite been able to put my finger on it. I still think there are some cool things in XEmacs that I’d like to see in GNU Emacs.
I’m especially looking forward to a really usable Emacs for Mac OS X. Ideally, it would be Cocoa rather than Carbon, and would behave just slightly more like other Mac OS X applications. (I generally hate Mac OS editors – my old favorite was Alpha, in the absence of Emacs.)
I’ve mostly been using SubEthaEdit for HTML and CSS and TeXShop for minor LaTeX editing, but I’ve just built a new CVS Emacs and it looks really great. (It also looks like it handles PDFTeX? and display pretty similarly to TeXShop, which is very cool.) I added some information about building it for DarwinPorts to the EmacsForMacOS page. Now all I have to do is port my .emacs over…. --ClaireConnelly