Zend Framework (ZF) is an open source framework for developing web applications and services with PHP 5. ZF is implemented using 100% object-oriented code. The component structure of ZF is somewhat unique; each component is designed with few dependencies on other components. This loosely coupled architecture allows developers to use components individually. 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. ZF 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_Auth and Zend_Acl, provide user authentication and authorization against all common credential stores. Still others 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.
The principal sponsor of the Zend Framework project 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 ZF community. Community members, including contributors, make themselves available on » mailing lists, » IRC channels, and other forums. Whatever question you have about ZF, the community is always available to address it.