If the manual for the Zend Framework provides just a bit too much detail, and you just want a general overview of the packages in the Framework, check out this quick list from Justin Silverton.

The Zend Framework is a recently released (still in alpha) set of open source tools for php designed for developing Applications and Web Services.

He describes the pakcages offered with this edition of the Preview Release including Zend_Db, Zend_HttpClient, Zend_InputFilter, and Zend_Log. For each, he provides a quick summary of what it can do. If you want anything more substantial than that, you'll need to head back to the manual.