The Zend Framework, from the creators of the PHP runtime, combines a business-friendly open source license with a set of high-quality, object-oriented component libraries for building serious Web applications. The loosely coupled components extend from authentication and session management to Web services and APIs to the popular Web 2.0 sites, and they include everything in between. You'll also find components for the MVC (model-view-controller) design pattern and "RAD" tools to generate your project structure and populate it with MVC components, but you're never locked in. You can take it just as much as you need and leave the rest.
License: New BSD License
The Bossies 2010 index:
Bossie Awards 2010: The best open source software of the year
Bossie Awards 2010: The best open source applications
Bossie Awards 2010: The best open source application development software
Bossie Awards 2010: The best open source platforms and middleware
Bossie Awards 2010: The best open source networking software
