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...
enquire.js : A lightweight, pure JavaScript library for responding to CSS media queries.
jQuery Masonry : A dynamic layout plugin for jQuery
The flip-side of CSS floats
emotion : emotion is a high performance, lightweight css-in-js library that supports both string and object based styles.
Selectivizr : CSS3 pseudo-class and attribute selectors for IE 6-8
