Something not mentioned much when discussing MVC* is that each part often runs in its own process and each have distinct constraints, or performance characteris

Something not mentioned much when discussing MVC* is that each part often runs in its own process and each have distinct constraints, or performance characteristics. View is dependent on graphics rendering, Model is often dependent on IO, and Controller is typically dependent on User. In contrast to the author, I consider MVC to be a very well defined concept. However it is a concept and the implementation details are left to each specific application. In fact in any GUI there are multiple incarnations of the MVC paradigm each designed to their specific responsibility and happily ignorant of the others.