If you are familiar with Zend Framework, you likely understand the concept of a Module in some detail. A Module is, in theory, a reusable collection of controllers, views and other classes which is packaged in its own directory for simpler copying or seperate treatment in a version control system like git or subversion.

The "resuable" part was stumping him until he figured out a way, using the Zend_Application component and a few add-on classes, plugins and configuration instances to create a proof of concept for making a simple module.