HTML5test.com
html5test.com (xhtml-mp)
I recently discovered Niels Leenheer's HTML5Test.com. It's another test suite that attempts to measure a browser's support for components of the HTML (formerly HTML5) and CSS3 draft specs. Like the W3C's Web Compatibility Test for Mobile Browsers - version 2 this one assigns a numeric score representing the browsers overall compliance with the specs. It shows pass/fail grades for each individual test as well.
As Niels points out, his test is not complete and doesn't cover all the fetaures of the HTML5 draft spec yet. It also tests some things that aren't part of HTML5 or CSS3 such as microdata support and which video and audio codecs are available. And unlike with the W3C test it doesn't seem to be possible to see tabulated results for all browsers tested.
Comparing browsers against spec compliance benchmarks is interesting too but I think too much is made of there being a "race" between browsers to achieve the best score on these tests. What really matters to developers is whether a given browser supports what they are trying to build. To end users all that matters is that the sites they want to use look and work well in their browser.
Html5test.com uses media queries to detect mobile browsers and reformat the results into a single fit to width column for them. That seems to work well well with any browser with any HTML5 feature support.