There are so many variations of MVC and this is a good thing. The important point of MVC is to separate concerns properly. One reason for the many variations is

There are so many variations of MVC and this is a good thing. The important point of MVC is to separate concerns properly. One reason for the many variations is that there are different concerns when in the browser vs on the desktop vs in Silverlight/Flash. For example, @fzzy mentioned the controller in smalltalk being used to poll the mouse & keyboard. In the browser, you don't have the same issues-- you can listen for events to be fired. Also, for example, in the browser, you have the DOM, which is communicated with and manipulated differently than UI widgets on the desktop. You'll find that all the MV* patterns (like MVC (in all its variations), MVP, MVVP, etc) have the concept of the domain model, and some object that's tightly coupled to the UI/DOM, and usually some middle layer. As long as you're using one of these types of patterns you'll least be able to take advantage the benefits that this family of patterns provides.