Zend Framework 2 is an open source framework for developing web applications and services with PHP 5.3+. Zend Framework 2 is implemented using 100% object-oriented code and uses most of the new features of PHP 5.3 such as namespaces, late static binding, lambda functions and closures.

Zend Framework 2 is the evolution of Zend Framework 1 a successfully PHP framework with more than 15 million of downloads. Because we used the new features of the PHP 5.3, ZF2 is not backward compatible with ZF1 that requires PHP 5.2. We also tested ZF2 on PHP 5.4 and it works fine but we decided to have PHP 5.3 as requirement.

The component structure of Zend Framework 2 is somewhat unique; each component is designed with few dependencies on other components. During the implementation we followed the SOLID object oriented design principle. This loosely coupled architecture allows developers to use components individually (we support Pyrus and Composer). We often call this a “use-at-will” design.

While they can be used separately, Zend Framework components in the standard library form a powerful and extensible web application framework when combined. Zend Framework offers a robust, high performance MVC implementation, a database abstraction that is simple to use, and a forms component that implements HTML form rendering, validation, and filtering so that developers can consolidate all of these operations using one easy-to-use, object oriented interface. Other components, such as Zend\Authentication and Zend\Permissions\Acl, provide user authentication and authorization against all common credential stores.

Still others, with the ZendService namespace, implement client libraries to simply access to the most popular web services available. Whatever your application needs are, you’re likely to find a Zend Framework component that can be used to dramatically reduce development time with a thoroughly tested foundation. We use PHPUnit to test our code and Travis CI as continuous integration service.

The principal sponsor of the project ‘Zend Framework’ is Zend Technologies, but many companies have contributed components or significant features to the framework. Companies such as Google, Microsoft, and StrikeIron have partnered with Zend to provide interfaces to web services and other technologies that they wish to make available to Zend Framework developers.

Zend Framework could not deliver and support all of these features without the help of the vibrant Zend Framework community. Community members, including contributors, make themselves available on mailing lists, IRC channels, and other forums. Whatever question you have about Zend Framework, the community is always available to address it.