HTML5 Boilerplate : HTML5 Boilerplate helps you build fast, robust, and adaptable web apps or sites. Kick-start your project with the combined knowledge and effort of 100...
Selectivizr : CSS3 pseudo-class and attribute selectors for IE 6-8
When can I use... : Compatibility tables for support of HTML5, CSS3, SVG and more in desktop and mobile browsers.
Mobile HTML5 compatibility : HTML5 compatibility on mobile and tablet browsers with testing on real devices
Mobello : Mobello is high performance javascript UI framework for HTML5 mobile app
‘320 and Up’ is a lightweight, easy to use and content first responsive web design boilerplate.