Zend_Layout: Part of the Zend Framework that combines the ideas behind Composite view and Two Step View
There are two design patterns that Zend Framework uses to implement layouts: » Two Step View and » Composite View. Two Step View is usually associated with the » Transform View pattern; the basic idea is that your application view creates a representation that is then injected into the master view for final transformation. The Composite View pattern deals with a view made of one or more atomic, application views.
In Zend Framework, Zend_Layout combines the ideas behind these patterns. Instead of each action view script needing to include site-wide artifacts, they can simply focus on their own responsibilities.