"The reality is that IE9 is 2 years late. Microsoft is glad to come out with the <video> tag, the <canvas> tag, SVG, and some CSS3. Like other vendors did years ago. Firefox 3.5 had the <video> tag, the <canvas> tag, Geolocation, SVG in 2009. Canvas and SVG existed 5 years ago."
Don't forget XHTML too.
I don't think XHTML is particularly relevant to web browsers these days. It's still useful as a format for storing documents, but I don't see it going anywhere as a widespread format for sending documents to web browsers.
Even on sites that claim to be serving XHTML, actual adoption is pretty low. You have to set the content type in the HTTP headers (no meta tag — the actual header) to "application/xml+xhtml" or you're actually just serving quirky HTML, and most sites don't bother, because HTML turns out to be perfectly sufficient and they don't realize they're doing it wrong (+ the old IE bugs with XHTML).
For example, look at the source for W3Schools.com. Then use Firebug or curl to look at the headers. That is an HTML page that thinks it's XHTML. The poor thing is addled.
At any rate, we've done without XHTML for quite some time now.
Yea, more precisely the lack of support, which was exactly what I was referring to in the OP. Particularly how it lasted for 11 years after XHTML 1.0 became a recommendation.
Actually XHTML has been abandoned, this is because in the standard it says if the browser finds a syntax error it should give an error and not render the rest of the page.
Pretty much all browservendors and webdevelopers think this was a bad idea to begin with.
