It is interesting to note that the webpage says “Standards aren’t add-ons to the web. They are the web. And you can start using them today.” However, in order to experience these “Standards” you will have to “add-on” Safari as your desktop browser. A blog post on Opera community claims that the reason behind the web page not working in the other browsers is:
Apple claim to promote HTML5 and an open Web, but the page uses browser sniffing to block other browsers, vendor prefixes for the CSS3 stuff they are using (even if other browsers support border-radius it won’t work because it’s coded using -webkit-border-radius), and the patent-encumbered H.264 for video.