This chapter covers the classes of the Application Kit. The Application Kit implements all of the graphical user interface components of Cocoa, including the complete standard Aqua widget set. Additionally, the Application Kit provides classes for interacting with the Quartz 2D drawing system, and for managing and accessing resources such as colors, fonts, and printers. The Application Kit is discusses in Chapter 3. Chapter 4 and Chapter 5 go into more detail about aspects of the Application Kit.