Recommendation of a JavaScript (GUI) framework to act as a frontend to a website's backend?

I'd like to tap your experience regarding the use/deployment of a JavaScript powered framework to implement a GUI frontend for different backend tasks.

The framework would have to provide a managable way of displaying arbitrary data fetched from a database (data can be provided in every thinkable way JSON, XML etc.) and allow the manipulation of that data by means of a clean and RESTful API. Prebuilt widgets (tables/lists/dashboard) and UI (drag'n'drop/sorting) would be nice to have but aren't mandatory.

The requirements are:

• Open Source (obligatory)
• clean and RESTful API to fetch, display and manipulate data
• Ability 开发者_JAVA百科to extend the functionality thru plugins
• Standards-compliant (IE does not have to be supported)
• Thorough documentation and/or helpful community

I've figured that jQuery's UI framework comes very close to the ideal, though it lacks a decent support of general structures to master a full-fledged application.

I'm interested of what you guys would recommend.

Thanks in advance.

After years of using several of the available frameworks I now use Yahoo's YUI3 (3 - not the older 2) if I can - for "serious" apps. For HTML page enhancements I'm indifferent and may sometimes prefer jQuery.

http://developer.yahoo.com/yui/3/ (BSD license)

What I like about YUI3 are the very "deep" concepts behind it for serious "enterprise level" software development. Regardless of what framework one uses, EVERYONE seriously developing in JS should have viewed (and understood!) the videos on Yahoo Developer Theater, especially the presentations by Douglas Crockford.

http://developer.yahoo.com/yui/theater/