title: What other MVC-like design patterns/architectures are there for highly flexible applications?
body: <p>A while back i read somewhere about how to improve upon the MVC pattern to accomodate the highly flexible and layered (web)applications we see today. (and to my frustration, i can't seem to find that article again)</p>
  
  <p>For example, some of the Google applications like GMail or even a browser like Firefox. </p>
  
  <p>It consists of components that can be extended and completely replaced. Users can choose the user interface or theme they like, has some kind of plugin system, etc etc...</p>
  
  <p>Owkay I know, this is how big/great applications are build. That's why i ask this question.</p>
  
  <p>Could you provide me with resources or insight in what patterns are used or how these applications are build architecturally...</p>