aw man, I opened this in Fx and Ch, hoping they'd done some html acrobatics and got it displaying completely differently in each browser but, actually, their site looks exactly the same in every browser...

I think it's from a while back (it's Dan Cederholm's push to help people get over that concern).

Also Firefox and Chrome almost certainly aren't the browser people would be worried about in such a case. Break out a vm and try an older version of IE.