http://www.koala-framework.org/
open source framework for web applications and websites
Powered by Php, Zend Framework, ExtJS and MySQL.
Build desktop like web applications with the power of Zend Framework and ExtJS - and Koala Framework as glue that makes writing smart applications as easy as possible.
Koala Framework CMS makes building websites fun. Use and combine the components shipped with Koala and just concentrate on the design and layout of your website - you will get a AJAX based, easy to use backend for free.