[domenicd]

This is pretty much the opposite of how things went down.

If browsers followed the W3C, we'd be living in XML utopia (XHTML2, XForms, XLink, XEvents, etc.). In 2004 a group of implementers (specifically Mozilla, Opera, and Apple) proposed to the W3C to focus on web applications by evolving HTML and the DOM, but were flat-out turned down, and had to go off and form their own standards organization---the WHATWG. Today, that is where much of the foundational work of the web platform is still done: https://spec.whatwg.org/

[pjmlp]

And we could have goten something similar to XAML, instead of the HTML, CSS magic and JavaScript workarounds to replicate desktop behavious and UIs.

[coldtea]

Do the names XHTML2, XForms, XLink, XEvents invoke an image of something like XAML to you?

We would have ended in some huge JAVA EE circa 2004 mess, with XML to spare and perhaps RDF and a couple ad-hoc languages thrown in for good measure.

[pjmlp]

Yes, because in the XHTML world, tags could loose any semantic meaning.

In HTML 5, one is abandoned to the CSS tricks and JavaScript hacks to make visual UI components of HTML tags.

Every time I get a consultant gig outside the web world, I rejoice.

Yet I've spend a big part of my career involved in web development.