The Zope 3 Book/Buildout

What is Buildout ?
From the buildout.zope.org site: ''Buildout is a system for managing development buildouts. While often identified as a Zope project, and indeed licensed under the ZPL by Zope creator Jim Fulton, buildout is useful for configurations beyond Zope, and even, in rare cases, a few that have nothing to do with Python.''