I saw just two examples:
I've been told that those effects are demos for pure HTML5 but is it really so?! Is there a way to code such cool stuff using only HTML5? Or do we still need to rely on JavaScript?
Furthermore, someone told me that one can build a solution using HTML5 and then compile it into Android and IOS at the same time. Is that correct?
I seem to have hard time finding info on the advanced part of HTML5. I only see Canvas tag in, Frameset tag out etc... What do i miss?
Everything gets labeled as HTML5 nowadays, even those things that have nothing to do with HTML5. So watch out for the hype. There are some amazing things I've seen done with CSS alone but that's not HTML5. Neither is Javascript. Don't be fooled. Read the source.
No. HTML5 doesn't do much on its own.
From http://mashable.com/2011/03/17/javascript-html5/:
Although HTML5 is its own standard, the power of HTML5 is really
only best realized with the use of CSS 3 and JavaScript.
Though as others have mentioned, it's very common (in fact, I'd say more often than not) that the term "HTML5" connotes its use with all the other technologies, and not the standard in isolation.