Overview

Why IRC in Emacs?

1. You can have other Emacs buffers visible and have irchat either in a small buffer or not visible at all. For example, you can read USENET news with GNUS without leaving irc, and be noticed if someone is trying to reach you. Nowadays when computing power is cheap you can have multiple emacses running so this view has lost some of its importance.
2. You get all the GNU Emacs features such as a calculator, all usable while in IRC. And you can run your favourite shell commands and get their output directly to IRC or to your input (*IRC Commands*) buffer for you to send to IRC channel.
3. You can edit other files while talking about their contents on IRC.
4. The commands for editing your text are those familiar from GNU Emacs and if you have customized them, the customized editing keys are automatically available. Irchat uses it's own keymap bound to C-c, so if you have used that key in your own keybindings you have to do some reordering in order to use your own commands.
5. You may easily add features if you find something missing (assuming you know elisp, of course, but this is a good reason to learn. ;)) Actually we are now (01-07.1991) working on a easily modifiable hooks to irchat (something like /ON on ircII - one of the most popular irc clients).
6. GNU Emacs has been ported on many different UNIX machines, so you will not have to do the porting yourself, which might be the case with the traditional clients.
7. If you use IRC on several machines, you don't need to compile an IRC client for all of them. You can just take the small elisp code with you and use it.
8. GNU Emacs tries to handle most terminals, which might not be the case with the traditional clients.