Materialize CSS - A modern responsive front-end framework based on Material Design
Foundation - The most advanced responsive front-end framework in the world
Bootstrap - Simple and flexible HTML, CSS, and JS for popular UI components and interactions
Semantic UI - A UI Component library implemented using a set of specifications designed around natural language
Spectre.css - Lightweight, responsive and modern CSS framework for faster and extensible development.
Ionic - Ionic is a cross-platform mobile development stack for building performant apps on all platforms with open web technologies.