MacOSXにhomebrew版Emacsをインストール

インストールコマンドは簡単。

$ brew install --cocoa emacs

インストールが終わったらこんなメッセージが。

Emacs.app was installed to:
  /usr/local/Cellar/emacs/24.1

Command-line emacs can be used by setting up an alias:
  alias emacs="/usr/local/Cellar/emacs/24.1/Emacs.app/Contents/MacOS/Emacs -nw"

 To link the application to a normal Mac OS X location:
   brew linkapps
 or:
   ln -s /usr/local/Cellar/emacs/24.1/Emacs.app /Applications

Because the official bazaar repository might be slow, we include an option for
pulling HEAD from an unofficial Git mirror:

  brew install emacs --HEAD --use-git-head

There is inevitably some lag between checkins made to the official Emacs bazaar
repository and their appearance on the Savannah mirror. See
http://git.savannah.gnu.org/cgit/emacs.git for the mirror's status. The Emacs
devs do not provide support for the git mirror, and they might reject bug
reports filed with git version information. Use it at your own risk.
==> Summary
/usr/local/Cellar/emacs/24.1: 3887 files, 118M, built in 6.1 minutes

ということで

$ ln -s /usr/local/Cellar/emacs/24.1/Emacs.app /Applications

これでLaunchPadとかからもEmacsが起動できるようになる。