Update emacs that comes with OS X
Apple controls when / if they update emacs so most people just install a newer version of the tool and change their PATH variable so the new version is found first and runs by default.

If you like the sound of that, I recommend installing Homebrew:

/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"


Then install emacs:

brew install emacs


Add a link so that it'll work as emacs in the Terminal:

ln -s /usr/local/Cellar/emacs/24.5/Emacs.app /Applications


This will install the 'stable' version. As of this writing, that's 24.5:

» brew info emacs
emacs: stable 24.5 (bottled), devel 25.0-dev, HEAD
GNU Emacs text editor
https://www.gnu.org/software/emacs/


This is significantly newer (24.5.1) than the version that came with El Capitan (22.1.1):

» emacs --version
GNU Emacs 22.1.1