Until this point, this book has focused on Cocoa's core frameworks, Foundation and Application Kit. However, Mac OS X contains many frameworks that you can leverage. Just look in /System/Libraray/Frameworks to see how many there are, or launch the Apple System Profiler (/Applications/Utilities) and click on the Frameworks tab.
Not all frameworks, however, are implemented in Objective-C, as are the Foundation framework and Application Kit. Most Mac OS X frameworks are implemented in C since that language provides the most universal API that can be accessed by the widest range of application environments, including Cocoa. Several newer frameworks provide Objective-C interfaces in addition to C.
This chapter looks at some of the Objective-C frameworks provided by Apple. However, Apple isn't the only provider of frameworks. Many free and commercially available Objective-C frameworks are offered by other developers. Several of these third-party frameworks will be mentioned at the end of the chapter. This chapter covers additional Objective-C frameworks, including:
Provides classes that allow applications to interface with Mac OS X's global Address Book database.
This small framework provides services to applications for sending email messages.
These two frameworks provide access to the system's disc recording APIs, giving any Cocoa application the ability to burn data to CDs and DVDs.