The funny thing is that HTTP and HTML was designed to support this sort of thing right from the start. That's why the DELETE request and friends was there from the start -- so that you could update a website. The first web browser was also a WYSIWYG editor. It's somewhat disappointing how long it took for this sort of functionality to come back.
Around 1995/6 I played with GNNPress, a browser/editor that implemented the "original" vision of the Web: you could GET a page, view it, WYSIWYG edit it, then PUT it back to the server. Unfortunately, that vision isn't really compatible with templating and CMSes, since you want to edit the "source" version of the page, not the "object code" HTML that comes out of the CMS.
