Gridless is an awesome HTML5 and CSS3 boilerplate for making responsive, cross-browser websites with beautiful typography
The spiritual successor to Less Framework
Adapt.js serves CSS based on screen width.
Automatically adapts your existing HTML images for mobile devices. No mark-up changes needed.
This is the new 320 and Up
Determine current page dimensions and current media query
Ultra–Lean HTML Building Blocks for Rapid Website Production
Supercharge your website