[html4all] "Blue sky thinking" (or "Thinking out of the box")

[Philip TAYLOR]

Leaving aside content-negotiation for the time being,
another "blue sky" idea struck me whilst I was mulling
over the various ideas that WHAT WG have rejected.
The one on which I homed in was the idea of DTD-based
parsing.  At the moment, the WHAT WG have rejected
the idea of allowing pre-HTML 5 documents to be parsed
differently from HTML 5, as a result of which HTML 5
is forced to carry all the baggage of ten years of
abuse of earlier specifications.  The justification
for this is that code-bloat is the one thing that
developers fear more than anything, and the idea
of having to have two (or more) parsers in a single
browser is simply unacceptable to them.  This is
where "blue skies" thinking comes in.

Suppose that a browser consisted of no more
than a DTD recognition element and a user interface.
On detecting any given DTD, the browser would
download the corresponding parser from the web,
and then commence parsing.  Caching would of
course be a vital part of this, so only the
first instance of any given DTD would involve
significant delay, after which all future
documents specifying that DTD would be processed
as speedily as they are today.

Benefits : tiny footprint, easy and unlimited
extensibility.

Drawbacks : over to you !

** Phil.