Before Emacs 24 the only way to benefit from third party elisp packages was to copy them to your configuration. RMS always opposed a package manager in Emacs because it would make it too easy to install non-free additions (this might not be a 100% accurate represetation of what happened, it’s what I remember hearing/reading).
In any case, Emacs 24 shipped with package.el, so now there’s a package manager. You can do M-x list-packages
and it will fetch a list of packages from one or more package repositories. You find the package you want, type i
, then x
and it installs.
There are a few different repositories. The “official” one from GNU is called ELPA. The most popular one with lots more than ELPA is MELPA. Here is how you add MELPA to your config: