Web Temptations did the HTML5Test.com in a posting 3 years ago - so lets see who is where 3 years later:
So what has happened in 3 years time? First all of the top 3 browser have gotten a lot better at delivering HTML5 they deliver 90% or better HTML5 compliance versus an average of 70% compliance 3 years ago. Also there are new members in the top 3 - Maxathon is the new top browser, Chrome follows at second and Opera a close 3rd. Gone from the top 3 are Firefox and Safari.
In fact the rumors that Apple's Tim Cook is stealing a PROPRIETARY PAGE FROM THE Microsoft Playbook are true - Apple has not only forced a fork in the Webkit alliance [Google and Opera have created a Webkit fork called Blink] but Apple is also moving fast towards last in HTML5 compliance. But the honor of being last in HTML5 support is reserved for Microsoft IE. It seems that even under new CEO Nadella, Microsoft has retained its antipathy to standards based web browsing.