HTML5 Up offering you the free yet responsive HTML5 and CSS3 based templates for website owners to build the web more faster, flexible and responsible to people out there. This provides more than 10+ free responsive templates. If you are a web designer you tweak these templates easily and customize them as you want them.
Some Features of HTML5 UP:
- Fully Responsive in Major and up-to-dated Browsers
- Built with HTML5 + CSS3
- Highly Customizable
Actually, HTML5 Up uses Skel.js script to provide responsive designs. Check out What Skel.js is?