On PHPBuilder.com today there's a new tutorial that introduces you to the PRADO framework and some of what it has to offer as another component-based tool (similar to how the Zend Framework is set up).

PRADO is a component-based and event-driven Web programming framework for PHP 5. A PRADO component represents a combination of a PHP class, an HTML template and a specification file (in XML). PRADO components are combined to form larger components or form complete PRADO pages. Developing PRADO Web applications involves instantiating pre-built and application-specific component types, configuring them by setting their properties, responding to their events by writing handler functions, and composing them into application tasks.

They walk you through the download and installation of the framework and include some sample scripts to show how it all works together. There's also an example of the optional application.xml file that lets you define different settings for your app, either application-wide or down to each module.