I just start to learn web programming, first lesson we study html, I believe our text book content is out of date? It state XHTML is the future...
But I seldom hear about it today now?
I Google and found 2 old blogs described about how XHTML will not dominant .
XHTML bad idea.
Validation does not matter.
Today, I only know HTML5 is mainstream client side markup language now...
Where XHTML go today?

  • Questions here should be about specific issues and problems regarding operating websites. This question is subject to opinions, will invite discussions, and is too broadly scoped for the format of this site. – dan Aug 30 '17 at 3:19

Please, check Joey's answer on this:

If your HTML is going to be regularly processed by automated tools instead of being read by humans, then you might want to use XHTML because of its more strict structure and being XML it's more easy to parse (from an application standpoint. Not that XML is inherently easy to parse, though).

You can see all the discussion here: At the end of the day, why choose XHTML over HTML?

  • 1
    I appreciate your answer, if you want precise communication, strict is need, because generally machines have no grey, only black and white. But l like to make my concept clean, no offense. If from the application standpoint, we can choose XML directly. Why XHTML. And I feel it depends on what automation tools is, if it is a search engine crawler, it can tolerance to the sloppy code errors. Back to my question, what really care XHTML today? What automation tools need it? I want an example to make my concept clear. No offense. Thanks @ribluc – user20757 Aug 30 '17 at 0:39