Much of the technology embodied by Apple's Cocoa software development frameworks have been in commercial use since 1988, and in spite of many years of use, the Cocoa frameworks are still revolutionary. Cocoa technology has been marketed with a variety of names including NeXTstep, OpenStep*, Rhapsody, and Yellow Box. In recent years, Apple has expanded the frameworks dramatically and added new tools to raise the bar for Cocoa programmer productivity beyond its already famously high levels.

Programmers are often overwhelmed by the breadth and sophistication of Cocoa when they first start using the frameworks. Cocoa is huge, but it’s also elegant in its consistency and simplicity which result from the application of patterns throughout its design. Understanding the patterns enables the most effective use of the frameworks and serves as a guide for writing your own applications.

This book explains the object-oriented design patterns found in Apple’s Cocoa frameworks. Design patterns aren't unique to Cocoa; they're recognized in most reusable software libraries and available in any software development environment. Design patterns simply identify recurring software problems and best practices for solving them. The primary goal of this book is to supply insight into the design and rationale of Cocoa, but with that insight, you'll be able to effectively re-use the tried and true patterns in your own software - even if you aren't using Cocoa.