(X)HTML5 is the accepted successor to (X)HTML [HTML4/XHTML1.x] XHTML2 is a branch standard of XHTML (there is no HTML equiv to it) with different goals, purposes, and isn't even widely implemented enough to be considered something viable for use. It's unlikely many browser vendors are even going to implement support for it. But it is afact that something called XHTML2 exists and it has nothing to do with HTML5. I'm just piping up against the misnomer of using the name "XHTML2" when you are actually referring to "XHTML5".
Though on the note... as I believe when it comes to it the doctype and what kind of stuff you use/the browser uses have little to do with each other. Using an old (X)HTML doctype, I believe browsers that support it will still make use of the <canvas /> element even though you're /supposed/ to use a (X)HTML5 doctype. The DOCTYPE merely controls validation, and what browsers you want in quirksmode, almost-standards, or standards mode. It might control parsing a little, but to be honest the content-type is really the only thing that at least Firefox considers for that. Even using a XHTML doctype Firefox still parses your document using loose HTML rules. It doesn't parse it with an XML parser unless you use application/xhtml+xml.
To be honest I've been on the personal debate lately on whether XHTML is really viable. Or if it's better to just have my applications start spitting out clean HTML with a HTML doctype rather than using XHTML. Most browsers don't bother with the XML factor of XHTML, the fancy parts of XHTML (like inline svg or more importantly, your own custom namespaces) aren't widely supported enough, CSS can't style namespaced nodes (Except in IE, which is strange because IE is the single browser that makes the whole XHTML as XML factor lag), using an actual XML generator to output your XHTML pages can cause invalid pages to be outputted (script tags may likely be outputted as <script src="..."/> which breaks in all browsers except FF2 (FF3 purposefully makes that break for it now), and an empty span as <span/> which can cause issues when the browser doesn't parse the document using pure XML), and it's actually fairly trivial to take a generated XML document and modify it to be HTML.
~Daniel Friesen (Dantman, Nadir-Seen-Fire) [http://nadir-seen-fire.com] -Nadir-Point (http://nadir-point.com) -Wiki-Tools (http://wiki-tools.com) -MonkeyScript (http://monkeyscript.nadir-point.com) -Animepedia (http://anime.wikia.com) -Narutopedia (http://naruto.wikia.com) -Soul Eater Wiki (http://souleater.wikia.com)
Aryeh Gregor wrote:
On Sat, Jan 31, 2009 at 10:12 PM, Daniel Friesen dan_the_man@telus.net wrote:
Someone needs to read a good WP article before they start mentioning (X)HTML version numbers: http://en.wikipedia.org/wiki/XHTML
Both HTML5 and XHTML2 are successors to HTML4. That's all that's really relevant here. HTML5 has un-deprecated the "start" attribute of <ol>, so nobody should be worrying about HTML4's deprecation of it. (XHTML2 does appear to have removed the attribute, so I guess you could worry about it if you plan to move to XHTML2 in the future. But probably nobody is going to use XHTML2, and MediaWiki almost certainly isn't.)