Most popular HTML5 responsive frameworks in 2013

Twitter Bootstrap
Sleek, intuitive, and powerful front-end framework for faster and easier web development.
http://getbootstrap.com/


HTML5 Boilerplate
HTML5 Boilerplate helps you build fast, robust, and adaptable web apps or sites.
http://html5boilerplate.com/


Zurb Foundation
Foundation is the most advanced responsive front-end framework in the world.
http://foundation.zurb.com/

Modernizr
Modernizr is a JavaScript library that detects HTML5 and CSS3 features in the user’s browser.
http://modernizr.com/


Pure
A set of small, responsive CSS modules that you can use in every web project.
https://github.com/yui/pure/

Respond.js
A fast & lightweight polyfill for min/max-width CSS3 Media Queries (for IE 6-8, and more).
https://github.com/scottjehl/Respond