Bootstrap is the most popular CSS Framework for developing responsive and mobile-first websites.
Less CSS is a dynamic stylesheet language that extends the capabilities of CSS, allowing developers to write cleaner, more modular, and reusable stylesheets with features like variables, mixins, and nested rules.
Gridsome is a Vue.js-based static site generator that makes it easy to build fast and flexible websites and applications by leveraging modern web technologies like GraphQL, Webpack, and hot reloading
Gulp.js is an old but popular site building tool that automates various repetitive development tasks in web development, such as compiling Sass, minifying JavaScript, and optimizing images.