When can I use... : Compatibility tables for support of HTML5, CSS3, SVG and more in desktop and mobile browsers.
Explorer Exposed! : These CSS bugs are all found only in Internet Explorer, versions 5 and higher. To see the demos properly, they must be viewed in IE, of course.
Mobile HTML5 compatibility : HTML5 compatibility on mobile and tablet browsers with testing on real devices
Email Standards Project : The Email Standards Project is about working with email client developers and the design community to improve web standards support and accessibility ...
HTML: The Living Standard. A technical specification for Web developers.
