PHP Framework: CakePHP
The CakePHP framework makes developing applications in PHP easier than ever. After a short download of the source code, you can start making customized dynamic webapps in minutes. Cake follows the Model-View-Controller paradigm to the extreme and makes tedious tasks such as html form creation and validation a breeze. I just walked through the tutorial, and I have no doubt that this will change the way I program all my future applications.