---

Frameworks

A framework is a special type of bundle used to distribute shared resources, including library code, resource files, header files, and reference documentation. Frameworks offer a more flexible way to distribute shared code that you might otherwise put into a dynamic shared library. Whereas image files and localized strings for a dynamic shared library would normally be installed in a separate location from the library itself, in a framework they are integral to the framework bundle. Frameworks also have a version control mechanism that makes it possible to distribute multiple versions of a framework in the same framework bundle.

Apple uses frameworks to distribute the public interfaces of Mac OS X. You can use frameworks to distribute public code and interfaces created by your company. You can also use frameworks to develop private shared libraries that you can then embed in your applications.

You can develop frameworks using any programming language you choose; however, it is best to choose a language that makes it easy to update the framework later. Apple frameworks generally export programmatic interfaces in either ANSI C or Objective-C. Both of these languages have a well-defined export structure that makes it easy to maintain compatibility between different revisions of the framework. Although it is possible to use other languages when creating frameworks, you may run into binary compatibility problems later when you update your framework code.

For information on the structure and composition of frameworks, see Framework Programming Guide. That document also contains details on how to create public and private frameworks with Xcode.

---