(ok, sorry I am just borrowing this wiki page)

The uber frameork. An application server (or at least what I understand by the term).

Just a generic way of re-using the same controllers and models for different front-ends

What is an application server?

Think Zope. (But zope is lacking GUI "targets".)

You can basically write any user application with it: website, gui application

Batteries included: any networking capabilities, ability to use any ORM.

Take a model, which can be accessed by any number of controllers, and in turn produce different types of view.

Why not use zope?

Have you actually used it?

What is the model?

The model is the data. Could be a database, or file or something.

How is the model stored?

You can use anything you like, files, orms, plain database calls, anything.

What is a controller?

I am imagining: that you register a controller for a model type, and execute it with some kind of request, and this would produce some kind of view.

What is a view?

More than what the user sees.

Could be a web page, could be some JSon, or XML or anything that the client (which might be us, or a browser, or an rss feed reader) can render visually.

How can I rewrite my application

Easy to port

especially existing standards, like WSGI