[html5] HTML5 without namespaces

Henri Sivonen hsivonen at iki.fi
Wed Jun 1 07:51:18 PDT 2011

On Wed, 2011-06-01 at 09:44 +0200, Jesper Tverskov wrote:
> As I have understood it, something more or less similar is under way
> to support RDFa inside HTML5 served with mimetype "text/html".
> http://dev.w3.org/html5/rdfa/rdfa-module.html
> I don't know if RDFa has to become part of the HTML5 spec to be
> integrated into HTML5 served with mimetype "text/html" or if there is
> some other way to allow RDFa inside HTML5?

RDFa is not integrated into HTML parsing. The group specifying RDFa uses
attributes of the form xmlns:foo, but those attributes are not namespace
declarations in text/html. The group specifying RDFa has been notified
about this repeatedly. While they have introduced alternative syntax,
they have refused to get rid of the xmlns:foo syntax even though
xmlns:foo is represented differently in the DOM in the text/html case
compared to the application/xhtml+xml case.

> Now my main question:
> What are our options, the day we would like to support other
> applications in HTML5, like, let us say "musicScoreML", "VoiceML",
> etc,  (I'm just making them up, for the argument, we don't care if
> they exist or if they are relevant to include or not)?

SVG and MathML were pre-existing languages and already implemented in
(some) browser engines. That's why they stayed in their namespaces. If
you are designing new vocabulary additions to the Web platform today,
putting the additions in the (X)HTML namespace avoids the problem of
having to introduce new namespaces.

Henri Sivonen
hsivonen at iki.fi

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