Materialize CSS - A modern responsive front-end framework based on Material Design
Unsemantic CSS Framework - Unsemantic is a fluid grid system that is the successor to the 960 Grid System.
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
960 Grid System - The 960 Grid System is an effort to streamline web development workflow by providing commonly used...
Semantic UI - A UI Component library implemented using a set of specifications designed around natural language