Learning GNU Emacs, 3rd Edition

Which Emacs Is Which?

Numerous versions of Emacs are available, offering a wide range of features, but two are in widespread use today: GNU Emacs and XEmacs. (An exhaustive list of Emacs implementations can be found at http://www.finseth.com/~fin/emacs.html.) XEmacs was originally tailored for GUI usage and has a fairly wide user base, but lacks some of the features of GNU Emacs.^[1]

This book covers GNU Emacs. Since its appearance, GNU Emacs has become the most popular, powerful, and flexible Emacs, and there's no reason to believe that this situation will change. If you know GNU Emacs, you will be able to adapt to any other Emacs implementation with no trouble; it's not so easy to go in the other direction.

This book, however, isn't limited to GNU Emacs users. Because of the similarities between different Emacs implementations, this book should help you get started with any Emacs editor. The basic keyboard commands change little from one editor to another—you'll find that C-n (for Ctrl-n) almost always means "move to the next line." Emacs editors tend to differ in the more advanced commands and features, but if you are using these more advanced facilities and you aren't using GNU Emacs, you should consider making the switch.

^[1] Quite a few issues come up in discussions of GNU Emacs versus XEmacs, with character encoding schemes, user interface differences, and copyright issues among them. We're not interested in taking sides in the battles between these emacsen.