Evaluating the art & spirit of PHP, Zend Framework is consists of object-oriented best practices, simplicity, rigorously tested agile codebase, and corporate friendly licensing. Zend Framework emphasizes on building more reliable, protected, and modern Web 2.0 applications & web services, and consuming widely available aPIs from leading vendors like Google, amazon, Yahoo!, Flickr, as well as aPI providers and cataloguers like ProgrammableWeb and StrikeIron.

Zend home page.