In today’s release of GitHub for Mac, you can now
easily install Git for use on the command line, without
needing to download any separate packages. And whenever we update the version of
Git included with GitHub for Mac, you’ll get the changes automatically – no
work required on your part!

After updating the app, you may notice some changes to the
Preferences window. On the newly renamed “Advanced” tab, simply click “Install
Command Line Tools”:

Advanced preferences pane

You’ll be prompted for an administrator password so that Git can be installed
into /usr/local/bin, and then you should very shortly see that it succeeded:

Installation Complete

If you’re using GitHub for Mac for the first time, and want to install Git, you
can also set it up from the welcome screen:

Configure Git welcome screen

Once installed, you can open up Terminal.app and run git commands to your
heart’s content. Command line aficionados, rejoice!

Update: We’ve since removed the ability to install Git from GitHub for Mac, because OS X Mavericks and later includes a version of Git already.