On Blancer.com they've posted what they call ten compelling reasons to use the Zend Framework for your next application (or even to rework a current one).

Trying to decide which framework to use for your new project? In this article, we’ll go in-depth about why Zend Framework should absolutely be your PHP framework of choice.

Their reasons cover a wide range of the framework's functionality including:

• Extend classes like there's no tomorrow
• Use what you need, forget everything else
• No model implementation choose your own adventure
• Guidelines and standards
• Community and documentation