HTML5 Boilerplate is the professional badass's base HTML/CSS/JS template for a fast, robust and future-proof site.
Initializr is a simple tool to help you getting started with an HTML5 project. It is built on HTML5 Boilerplate, a powerful HTML5 template created by Paul Irish and Divya Manian. Initializr will generate for you a clean customizable template based on Boil
selectivizr is a JavaScript utility that emulates CSS3 selectors in Internet Explorer 6-8
Check Browser Compatibility, Cross Platform Browser Test