If their page is entitled "web standards", it's probably a bad idea to restrict the page only to users of Safari. Especially when it shares a rendering engine with Chrome and a number of other browsers that could probably run the demos.
For the record, when Google created Chrome Experiments (which used HTML5-ish technologies), they let any browser attempt to run the experiments, but the performance (in some cases) suffered. Apple is doing exactly the opposite.
On the consumer accessible page Apple are requiring Safari because they can guarantee that the demos will work and they can guarantee they will have reasonable performance. And that's what's important. That's an advocacy page, a PR thing, not "look at this cool code we wrote". Presentation is everything.
In other words, different goals - different implementations.
the really important part of html5 at the end of the day is for CONSUMER, not developers.
Here Apple doing exactly what dumb people did when they started the browsers war 10 years ago "this site is best viewed with X",
which later degenerated to "if you don't have browser X, go f*ck off" (you know wars ... people pick a side).
A browser is not here to guarantee an experience, it's here to guarantee you to browse content, and wether this browser support whatever version of HTML, this browser should not be blocked in any arbitrary way because the HTML should gracefully degrade, yeah even with Lynx on a command line.
Odd, when I go there in Firefox I can get to the pages but if I click View Demo on any of them (well, I tried the first 3) it still yells at me and tells me that I need Safari.
> On the consumer accessible page Apple are requiring Safari because they can guarantee that the demos will work and they can guarantee they will have reasonable performance.
I'm sorry, how is that supporting standard again? I'm not illuminated yet.
I tried the demos in Firefox and Chrome. Not all of the demos worked in either of them, so much for "could probably". It's not about Safari trying to make itself look better, it's about Apple not letting html5 look bad. If someone not-so-knowledgeable surfed to the demos with browser X and not everything worked then they may proclaim that html5 is crappy and doesn't work. Apple is trying to show-off html5 and that would be the opposite of their goal.
They restrict it to Safari because the dire truth is that so far, Safari is that one browser that does the STANDARDIZED HTML5 portions best. Chrome hits the second place not far behind, not surprisingly since it also uses the WebKit engine. Firefox however, by many peoples' experience - and, again, using HTML5 demos that do not use vendor-specific CSS magic, APIs and whatnot - simply fails at running most of these demos.
add.: to the downvoters... really, just load the page up in Chrome, check the demos, then load it up in Opera (with User Agent spoofing) and check the demos there, THEN try loading it up in Firefox, and you'll see for yourself whether it's a case of these HTML5 demos being "proprietary", "Safari only" or "broken", or if it's a case of Firefox just not cutting it yet. (Spoiler: it's a case of Firefox just not cutting it yet; almost all of the demos work identically in Chrome and Opera.)
For the record, when Google created Chrome Experiments (which used HTML5-ish technologies), they let any browser attempt to run the experiments, but the performance (in some cases) suffered. Apple is doing exactly the opposite.