That's interesting. I've tried to google cf CLI however wasn't able to find good documentation.
Is it possible to install cf CLI on my server? Or is it Cloud Foundry tool only?
You'd use it for one in your own data centre, or Pivotal Web Services[0], or BlueMix. You point it at an API and login, then off you go.
If you need something more cut-down to play with, Lattice[1] is nifty, but currently doesn't do buildpack magic.