Onsen : Open source HTML5 hybrid app framework for PhoneGap & Cordova
Mobile-optimized HTML5, CSS and JavaScript with Web components
Responsive layout, Materi...
320 and up : ‘320 and Up’ is a lightweight, easy to use and content first responsive web design boilerplate.
lit : a ridiculously small responsive css framework
Skeleton : Skeleton: A Dead Simple, Responsive CSS Boilerplate for Mobile-Friendly Development
HTML5 Boilerplate helps you build fast, robust, and adaptable web apps or sites. Kick-start your project with the combined knowledge and effort of 100s of developers, all in one little package.