PHOCOA is an object-oriented, event-driven, componentized, MVC (model-view-controller) web application framework based on Apple's Cocoa architecture.
PHOCOA's primary intent is to make developing web applications in PHP easier, faster, and with fewer bugs. The framework handles most of the "dirty work" of programming by removing the need to write much glue code for data binding (moving data between the model layer and view layer of your application), validation, error handling, request processing, etc. Most of your time will be spent designing your GUI and writing application-specific logic rather than dealing with form data, database calls, etc.
As much as possible, PHOCOA aims to make it so that as much of the code you write as possible is specific to your own application.