Luke Keith recently submitted a link to a framework he and Samuel Dillow have been working on for the last two years and have just now released for public consumption - Jackal.

Writing incredibly powerful web sites and web apps has never been this easy. Every line in Jackal was carefully engineered for speed and efficiency. Our goal was to create a PHP framework that helps you write bigger better applications without getting in your way. Writing for the web is a lot of work if you start from ground zero. Using Jackal, you can immediately start writing your application because we have already built the foundation.

They've just released v1.1.3, and 1.2 will be coming along shortly. You can get more information about the framework and its use from the tutorials and documentation on the jackalphp.com site. The framework currently includes components for query buildings, RSS handling, templating and working with cURL.