" For more information, see: Event-driven_programming Implementations The pattern was first described in 1979 by Trygve Reenskaug, then working on Smalltalk at Xerox research labs. This original implementation inspired many other GUI frameworks such as: The NeXTSTEP and OPENSTEP development environments encourage the use of MVC . Cocoa, based on these technologies, also uses MVC. Microsoft Foundation Classes (MFC). The Java Swing GUI library. More recently there have been attempts to apply MVC architectures for web-based interfaces. In the design of web applications, MVC is also known as a "Model 2" architecture in Sun parlance. Model Portfolio Atlanta Complex web applications continue to be more difficult to design than traditional applications, and MVC is being pushed as a potential solution to these difficulties. Beware: many applications which claim to comply with this much misunderstood pattern in fact do not achieve the required separation of model and view. "

" For this reason (among others), many programming shops develop the user interface design early in the process of design, and freeze the interface early. The unfortunate side effect of this is that the domain of the problem often isn't clearly understood by the programmers until late in the implementation process. Thus, just at the time that the developers are finally competent to create a good interface, they are kept from changing it. MVC models allow the code to be more flexible later in the development process, allowing for changes that make sense at the time it makes sense to make them. Event driven In contrast, objects in object oriented programming are composed of methods and data members that attempt to model something from the domain of interest. The best models are fully encapsulated, meaning that they implement every aspect of that real world object of interest to the domain of interest, and that they don't have any extra code that doesn't model the real world. Encapsulation also means that the class is implemented in such a way that the internal representation of data is not exposed to the user of the object. Kid Model Portfolio The impedance mismatch between these two worlds, that of events, and that of objects, is something that's been recognized for a long time. Getting these two worlds to cooperate requires a lot of 'glue code' to make them work together. "