A PHP framework for web artisans
The Symfony PHP framework
SilverStripe Framework, the MVC framework that powers SilverStripe CMS
Yii 2: The Fast, Secure and Professional PHP Framework
The HttpKernel component provides a structured process for converting a Request into a Response.
Flat-files and plain-old PHP functions rockin'on as a set of general purpose high-level abstractions.
A powerful yet easy-to-use PHP micro-framework designed to help you build dynamic and robust Web applications - fast!
CakePHP: The Rapid Development Framework for PHP - Official Repository