The MVC pattern is honestly so simple it or something like it usually emerges from most UI architectures. I would argue that even the increasingly common backend vs. frontend separation is a form of MVC. Of course, MVC isn't synonymous with MVC frameworks.

When it comes to pure old MVC, I feel that it is a bit like Greenspun's tenth rule:

> Any sufficiently complicated C or Fortran program contains an ad hoc, informally-specified, bug-ridden, slow implementation of half of Common Lisp.

So any UI environment will eventually contain an architecture that more or less embodies the spirit of MVC.

And I think MVC is fine within a single environment. That means, the information travelling from the models to the controllers to the views does not contain intermediary where mediums are crossed. A traditional Rails application crosses from databases to a Ruby program to a web browser, and each bit of logic is dependent of the others.

What makes the backend/frontend separation such a good model is that a front running on a REST API is not inherently dependent on a protocol or a server implementation, and the same applies to the backend. This will work in the post-HTTP world, whenever that comes.

Traditional Rails apps assume they are talking to a web browser. This is assumption is no longer tenable.