Want to try some new JS UI framework? You can try W2UI. It just something like jQuery UI but W2UI is a lightweight version and only provide some essential features, functions and events.
It use a lot of HTML5 and CSS3 features inside the script and contained all the common UI widgets such as grid, layout, toolbar, sidebar, tabs, form, popup, validation and more.
Only 69kb in a single JS file and guarantee smaller than extJS and Kendo UI. Its free and open source, if you want to give some feedback or contribution to W2UI, they are happy to hear from you!
W2UI is released under MIT license.
Source: Read more about W2UI