This excellent post is a mix of history and possible futures:
As the WWW spread, it grew features. Soon, it was not enough for the documents to contain just text: support for images was added. People wanted to customize the look of the documents, so HTML gained presentational markup abilities, eventually obsoleted by CSS. It was not enough to be able to view the menu of your local pizza store – people wanted to actually order a pizza: the need for sessions yielded cookies and non-idempotent HTTP methods. And people wanted the pages to be interactive, so they became scriptable.
All these features were good. They helped the Web meet actual needs. But having them has a significant consequence, one that is seldom realized:
We don’t have a Web of Documents anymore.
Daniel goes on to argue that what we have today is a Web of Applications, but he believes we can recreate the old web by adding just three restraints…