Ansible is a bit like puPHPet, in that it provisions Vagrant boxes etc. My latest project is using PPI Framework 2, and provisions with Ansible, so I had to get everything installed.
Essentially we just clone from the Github repo and install a few python things:
$ git clone git://github.com/ansible/ansible.git --recursive $ cd ansible $ source hacking/env-setup $ sudo easy_install pip $ sudo pip install paramiko PyYAML Jinja2 httplib2 six
And that should be you. Run ansible from the terminal in ay folder now and you should get all the available options etc. Have fun!