2 Chapter 1. Cocoa and Mac OS X IN THIS CHAPTER · · · · Understanding When to Use Cocoa Understanding Cocoa's Role in Mac OS X What You Need to Use Cocoa What's Included in Cocoa Cocoa is a collection of software objects that implements almost all features common to Mac OS X applications. Programmers extend the Cocoa objects to implement application-specific features. The Cocoa objects are reused in every Cocoa application so that programmers can concentrate on adding unique value with each line of code rather than constantly reimplementing common features or struggling to access operating system services. Significant applications can be built with very little code. Cocoa is the result of continuous evolution from the software development environment of NeXT-