I'd even go as far as saying it's barely usable at all.

You can't tell anything from it at a glance; you have to hover each "ray" one by one to know what it's about, and then most probably for at least the first 5 or 6 times look at the top left to know what browser each color represent; and you're supposed to know what each feature presented actually mean.

Welcome to HTML5! Completely overdone graphics with no usability (for a while anyway).

For those interested, this information can be found in table form on Wikipedia: http://en.wikipedia.org/wiki/Comparison_of_layout_engines_(H...

The intention of this visualization was to show how much support exists for a particular HTML5/CSS3 feature among the 8 browsers, but not which specific browser supports which feature, which are already covered well here: http://whencaniuse.com