When can I use... : Compatibility tables for support of HTML5, CSS3, SVG and more in desktop and mobile browsers.
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
Mobile HTML5 compatibility : HTML5 compatibility on mobile and tablet browsers with testing on real devices
The HTML5 Shiv : The HTML5 Shiv enables use of HTML5 sectioning elements in legacy Internet Explorer and provides basic HTML5 styling for Internet Explorer 6-9, Safari...
320 and up : ‘320 and Up’ is a lightweight, easy to use and content first responsive web design boilerplate.
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.