Ismo is an application framework written in PHP for PHP. It features industry accepted design solutions such as MVC (model-view-controller separation) yet remains easy and straightforward to use.
CodeIgniter is a powerful PHP framework with a very small footprint, built for developers who need a simple and elegant toolkit to create full-featured web applications.
Ambivalence is a Model-View-Controller framework for PHP web development. Based on the Java-based Maverick project, Ambivalence also offers clean MVC separation and an XML sitemap
CFWheels is an open source CFML (ColdFusion Markup Language) framework inspired by Ruby on Rails that provides fast application development, a great organization system for your code, and is just plain fun to use.