Is that HTML5?
Is that HTML5? No, so stop asking. Seriously, do you even know what it is you are asking? When you say a strange blanket thing like that, you may as well be saying "is that an internet?"
HTML5 is 99% semantics, stuff going on behind the scenes, not a visual thing. Or would you prefer I give my answer based purely on the doctype of the page Im using? Dont get me wrong, I think HTML5 is great, a lot of the markup and speed benefits are really nice; but canvas aside, its stuff that the user doesnt see happening, they just benefit from it. Sadly its again the case of HTML5 is being used as a buzz-word. Being thrown around by people who want to sound like they know what theyre talking about.
"Is that CSS3?" would be a far more sensible thing to ask. While it is still a bit of a buzz-word, it is at least relevant. After all, CSS is presentational, and all the nice things you see like transitions, gradients, opacity and shadows are CSS3. Things you would have previously had to do with JavaScript now can be done purely in CSS, and to my mind, the results is much better.
Thats all I wanted to say on the matter, just please stop saying it. Dont make me resent the word for something that I love.