Frameworks have been part of Cocoa since the days of NeXTStep. A framework is a kind of bundle, a directory that is meant to be treated as a single, indivisible unit (see Chapter 22, “Bundles and Packages,” for details). In the case of a framework, the directory contains a dynamic library, plus the resources—NIBs, image files, etc.—the library needs to provide an integrated, shareable, reusable package of services.
Frameworks are in wide use in OS X not just as open or commercial projects to pass among themselves, but as units of the operating system itself. Look in
/Library to find
Frameworks/ directories for every function in OS X that isn’t at the level of the Unix kernel.
As an offshoot of the Darwin ...