When can I use... : Compatibility tables for support of HTML5, CSS3, SVG and more in desktop and mobile browsers.
Introduction to WAI ARIA : This article is for those who are new to ARIA. You need an understanding of HTML and the potential difficulties that people with disabilities can face...
Mobile HTML5 compatibility : HTML5 compatibility on mobile and tablet browsers with testing on real devices
HTML5 Please : Look up HTML5, CSS3, etc features, know if they are ready for use, and if so find out how you should use them – with polyfills, fallbacks or as they
HTML5 Cross Browser Polyfills : So here we're collecting all the shims, fallbacks, and polyfills in order to implant html5 functionality in browsers that don't natively support them.
HTML: The Living Standard. A technical specification for Web developers.