In the simplest terms, an application framework is comprised of a library of classes that together, provide the most common functionality required by an application. By using an application framework, we can vastly reduce the amount of work and time that is required to create the various parts of the application. In short, they support the future development of the application.

In typical three-tier applications, the framework often extends through all layers of the application; the Presentation Layer, the Business Layer, and the Data Access Layer. In a WPF application using the MVVM pattern, we can therefore see aspects of the application framework in all three components of the pattern; the Models, the View Models, and the Views.

Apart from the obvious benefits of the reduced production times and effort involved in creating our application components, application frameworks also provide many additional benefits. Typical application frameworks promote reusability...