Spectre is a web application to diff screenshots.
A CSS framework that actually looks good.
Bulma is an open source CSS framework based on Flexbox and built with Sass. It's 100% responsive, fully modular, and available for free.
A lightweight and modular front-end framework for developing fast and powerful web interfaces
A modern responsive front-end framework based on Material Design
The most advanced responsive front-end framework in the world
A UI Component library implemented using a set of specifications designed around natural language
MUI is a lightweight HTML/CSS/JS framework that follows Google's Material Design guidelines