What makes a program a Cocoa program? It’s not really the language, because you can use a variety of languages in Cocoa development. It’s not the development tools, because you could create a Cocoa application from the command line (although that would be a complex, time-consuming task). No, what all Cocoa programs have in common—what makes them distinctive—is that they are composed of objects that inherit ultimately from the root class, NSObject, and that are ultimately based upon the Objective-C runtime. This statement is also true of all Cocoa frameworks.
