Yii is a high-performance component-based PHP framework best for
developing large-scale Web applications. Yii comes with a full stack
of features, including MVC, DAO/ActiveRecord, I18N/L10N, caching,
jQuery-based AJAX support, authentication and role-based access control,
scaffolding, input validation, widgets, events, theming, Web services,
and so on. Written in strict OOP, Yii is easy to use and is extremely
flexible and extensible.

WWW: http://www.yiiframework.com/