React.js, developed by Facebook, is a powerful JavaScript library for building interactive user interfaces. It allows developers to create reusable UI components, increasing efficiency and consistency across projects. React’s popularity is largely due to its virtual DOM feature, which enhances app performance.

Angular.js, a brainchild of Google, is a comprehensive framework used to build dynamic, single-page applications (SPAs). Angular comes with two-way data binding, dependency injection, and a modular architecture, making it a popular choice for enterprise-level applications.

Vue.js, created by Evan You, is a progressive JavaScript framework that's gaining popularity for its simplicity and flexibility. Its reactive two-way data binding and component-oriented development model make it an excellent choice for complex UI development.

Ember.js is an open-source JavaScript web framework that allows developers to create scalable single-page web applications. It comes with a robust set of features and adheres to the convention over configuration principle, reducing the amount of code developers need to write.

Backbone.js provides structure to web applications by allowing developers to create models that key-value binding and custom events. Its minimalistic design and RESTful JSON interface make it lightweight yet powerful.

Alpine.js offers the reactive and declarative nature of big frameworks like Vue or React at a much lower cost. It's used for sprinkling in a bit of interactivity into traditional server-rendered pages or enhancing simpler static sites.

Polymer, developed by Google, helps create custom, reusable HTML elements, and supports both one-way and two-way data binding.

Aurelia is a collection of modern JavaScript modules, enabling developers to create browser, mobile, and desktop applications. It allows for two-way data binding and has an extensible HTML compiler.

jQuery is a fast, small, and feature-rich JavaScript library that simplifies HTML document traversal, event handling, animation, and AJAX. It makes tasks that often require a lot of JavaScript code significantly simpler with an easy-to-use API.

Bootstrap is a powerful and popular CSS framework for responsive, mobile-first front-end web development. It contains CSS- and JavaScript-based design templates for typography, forms, buttons, navigation, and other interface components.

Foundation is a family of responsive front-end frameworks that makes it easy to design beautiful responsive websites, apps and emails that look amazing on any device. Foundation is semantic, readable, flexible, and completely customizable.

Semantic UI is a development framework that helps create beautiful, responsive layouts using human-friendly HTML. It emphasizes intuitive design with a massive library of pre-coded elements for quick prototyping and development.

Material-UI is a popular React UI framework that implements Google's Material Design. It provides developers with components to make a modern, visually appealing, and user-friendly interface.

Bulma is a free and open source CSS framework based on Flexbox. It's 100% responsive, fully modular, and available for free. It provides a lot of ready-to-use components, making it an excellent choice for rapid prototyping.