OS X El Capitan: The Missing Manual

Cocoa and Carbon

OS X can run two different kinds of programs, each with different characteristics: Cocoa and Carbon. (What follows is a technical discussion, but it’s loads of fun.)

When Apple invented Mac OS X, it gave the world’s software companies a choice:

• Update their existing programs (Carbon). If programmers were willing to put some effort into getting with the OS X program, they could simply adapt, or update, their existing software.

  The resulting software looks and feels almost like a true OS X program—but behind the scenes, the bulk of the computer programming was the same as it was in Mac OS 9. These are what Apple calls Carbonized programs, named for the technology (Carbon) that permits them to run on OS X.

  Most Carbonized programs don’t offer all the features available to OS X, however. In the following pages, you’ll discover which OS X goodies you sacrifice when using programs adapted this way.

• Write new programs from scratch (Cocoa). As OS X became more popular, more software companies created programs exclusively for it. The geeks call such programs Cocoa applications. Although they look exactly like Carbonized programs, they feel a little bit more smooth and solid. And they offer a number of special features that Carbonized programs don’t offer.

  These days, almost every name-brand program is a true Cocoa application, including Photoshop, Microsoft Office, FileMaker, iMovie, Safari, Messages, Photos, TextEdit, Stickies, Mail, Contacts, and so on.

The Cocoa Difference