Ext JS is a JavaScript framework for developing data-intensive, cross-platform web applications. It is built on a powerful, feature-packed library that provides an out-of-the-box solution for creating dynamic, visually stunning user interfaces. It is designed to provide developers with an easy-to-use, comprehensive set of tools and frameworks for building robust web applications. Ext JS is fast and flexible, with an intuitive API that makes coding easier and faster. It offers a wide range of UI components and widgets, such as grids, lists, tabs, forms, menus, and more, that can be used to create powerful web applications. It also has a powerful data package that allows developers to easily integrate with various data sources and create dynamic, data-driven applications. Ext JS also offers excellent support for mobile devices, as well as various themes and skins that can be used to customize the look and feel of the application. Overall, Ext JS is an ideal choice for developers who want to quickly create data-driven, feature-rich web applications.
Zepto does not provide a user interface toolkit.