Yana 4 PHP Framework. Free for non-commercial use,

freshmeat.net: "The Yana Framework is a component framework for developing PHP applications. It can be expanded with your own plugins (components). It includes skin and template support, multiple languages (German and English by default), mature administration functionality, multiple installation profiles, user login and administration, a database API based on PEAR-DB that also offers database schema support, and a GUI/code generator for your own plugins. It also includes an easy to use query tool that automatically maps database commands to a flat file if no database support is available. Plugins provided with this software are a guestbook, an RSS to HTML converter, and a search engine. Complete (German) documentation is included."

Mac's PHP MVC Framework with a CMS. GPL

SourceForge.net: "Mac's PHP MVC Framework is a open source, MVC Framework with an in-built templating engine and an integrated AJAX Driven CMS, it comes bundled with many PHP and Javascript libraries so you can focus on creating the application you want."

PHPulse is a highly scalable MVC framework for PHP. GPL

freshmeat.net: "It is extremely lightweight and fast, with a modular development environment that allows functionality to be added quickly and easily with a built in templating engine."