This is coming close to WWW's original vision because the very first web browser was also an editor. Tim Berners-Lee's application on the NeXT was basically a wrapper for the operating system's built-in rich text editing class named TextView. (It later became NSTextView on Apple's Mac OS X and still powers the TextEdit app on Mac.) We lost editing for two reasons: 1) The HTTP PUT method didn't exist yet, so edited HT…
To add to that the W3C maintained the Amaya "browser" , or web editor how they liked to call it, for like a decade and a half, as their vision for the web. I think it was not just an appealing idea but Amaya itself was a solid implementation for a "testbed" (again, their words). I can see why it died but I still think it is a bit of a shame it did.
> It supports HTML 4.01, XHTML 1.0, XHTML Basic, XHTML 1.1, HTTP 1.1, MathML 2.0, many CSS 2 features, and SVG.
Perfect. Doesn't need anything else.