Materialize CSS - A modern responsive front-end framework based on Material Design
Select2 - Select2 offers customizable select box with support for searching, tagging, infinite scrolling, and many other used options.
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
Material UI - A CSS Framework and a Set of React Components that Implement Google's Material Design
Semantic UI - A UI Component library implemented using a set of specifications designed around natural language