“Two nibs are better than one.”
Now that you know a bit about what makes Mac OS X tick, let's jump right in and create a document-based application using Cocoa. If you're reading this book, you might have created simple non–document-based applications in Cocoa. We'll be doing this throughout later chapters as test-bed programs are created. You know how simple they are to put together quickly. The document-based application, however, is a bit more complex. But once you see one examined, you will have little trouble creating your own.
Document-based applications allow a user to work with multiple documents at the same time. Whereas a non–document-based application usually has one window and can only manage one set ...