The feature detection checks that canvas.getContext("webgl") returns non-null. IE11 does indeed return null for that; it wants "experimental-webgl" instead
I meant "IE 11 user here", IE is just one of 3 browsers I use.
Yes, so the site owner should just fix the feature detection (webgl and experimental-webgl) - that's normal.
It used to be best practice to test a website in IE, Firefox and a WebKit based/originated browser (Chrome/Safari). Opening the site with Chrome now shows a dialog that apologize for limited testing, ok.
The docs mention this also: http://msdn.microsoft.com/en-us/library/ie/dn385811 (second example)