320 and up : ‘320 and Up’ is a lightweight, easy to use and content first responsive web design boilerplate.
Onsen : Open source HTML5 hybrid app framework for PhoneGap & Cordova
Mobile-optimized HTML5, CSS and JavaScript with Web components
Responsive layout, Materi...
Shards : A free and modern UI toolkit for web makers based on the popular Bootstrap 4 framework.
Ionic : The beautiful, open source front-end SDK for developing hybrid mobile apps with HTML5.
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.