What is it? What shoud I see? What does it demonstrate? I followed the link which opens an html/css/js editor in which I cannot do anything. After some search

What is it? What shoud I see? What does it demonstrate? I followed the link which opens an html/css/js editor in which I cannot do anything. After some search I saw a white page with a list of icon a radio button switching from png to svg and some text about framerate where I do not see any animation or any difference between the two!