jQuery UI is a collection of GUI widgets, animated visual effects, and themes implemented with jQuery, Cascading Style Sheets, and HTML. Developed by The jQuery Project
License: Open Source
w2ui is a lightweight framework focused on providing a rich set of UI components with excellent performance, while jQuery UI is a more extensive library built on jQuery that offers a wider range of components and customization options but comes with a larger footprint. The choice between them often depends on project requirements, performance considerations, and the need for specific UI components.