Archetypes is a framework for the development of new content types in Zope/CMF/Plone. Schema driven automatic form generation, simple integration with rich content types, and a lower entry bar to the complex requirements Zope places on new content objects.

http://sourceforge.net/projects/archetypes - CVS

http://plone.org/documentation/archetypes - documentation

Archetypes 1.2 API Documentation on ZDP (Created using epydoc)

Archetypes 1.2 UML Documentation on ZDP

A similar ZopeProduct is CPSSchemas.