There are many popular frameworks available for creating JavaScript UI widgets. Here are some of the most widely used ones:

1. React: A popular JavaScript library developed by Facebook for building UI components. It allows developers to build reusable UI components that can be easily integrated into larger applications.

2. Angular: A framework developed by Google for building complex, data-driven web applications. It includes a powerful templating system, two-way data binding, and a rich set of built-in directives.

3. Vue.js: A progressive JavaScript framework that allows developers to build user interfaces and single-page applications. It features a simple and easy-to-learn API, a powerful reactive system, and excellent performance.

4. jQuery UI: A popular plugin for the jQuery library that provides a set of user interface widgets, effects, and themes. It includes components like accordions, tabs, dialog boxes, sliders, and date pickers.

5. Materialize: A modern responsive front-end framework based on Google’s Material Design language. It provides a set of UI widgets and components that are easy to use and customizable.

6. Bootstrap: A popular front-end framework that provides a set of CSS and JavaScript components for building responsive, mobile-first websites and web applications. It includes components like modals, carousels, dropdowns, and forms.

7. Semantic UI: A modern front-end framework that provides a set of CSS and JavaScript components for building responsive and beautiful user interfaces. It includes components like grids, menus, forms, and modals.

These frameworks can help speed up the development process by providing pre-built UI components, and they often come with additional features like cross-browser compatibility, performance optimization, and accessibility features. Developers can choose the framework that best fits their project requirements and development style.