`hub` is a command line utility which adds GitHub knowledge to `git`.
It can used on its own or as a `git` wrapper.
Normal:
$ hub clone rtomayko/tilt
Expands to:
$ git clone git://github.com/rtomayko/tilt.git
Wrapping `git`:
$ git clone rack/rack
Expands to:
$ git clone git://github.com/rack/rack.git