Zend Framework 2
Zend Framework 2 is an open source framework for developing web applications and services using PHP 5.3+. Zend Framework 2 uses 100% object-oriented code and utilises most of the new features of PHP 5.3, namely namespaces, late static binding, lambda functions and closures.
The component structure of Zend Framework 2 is unique; each component is designed with few dependencies on other components. ZF2 follows the SOLID object oriented design principle. This loosely coupled architecture allows developers to use whichever components they want. We call this a "use-at-will" design. We support Pyrus and Composer as installation and dependency tracking mechanisms for the framework as a whole and for each component, further enhancing this design.
Source: Zend Technologies Ltd