I use emacs for email and news reader (gnus), Irc (rcirc), jabber (jabber.el), twitter (twittering-mode), calculator, password storage (PGP encrypted file), and

I use emacs for email and news reader (gnus), Irc (rcirc), jabber (jabber.el), twitter (twittering-mode), calculator, password storage (PGP encrypted file), and sysadmining (remote/sudo file editing with tramp). And I use it as my primary development envrionment. I get the same text editor capabilities if I'm writing a tweet, email or code. And yes, vim is a far superior editor. Luckily emacs implements that as well (evil or viper).