Wysiwyg javascript framework (build a builder)

Looking for a javascript framework that allows to build an online web component that builds other web components. I'll clarify: thinking about building a drag-n-drop/wysiwyg web appli开发者_运维百科cation that produces javascript pages/documents/dialogs etc.

I know that I can start from jQuery, however, if anyone can recommend a higher-level framework that will allow to build a "builder" (with toolbars, drag-n-drop etc) - please share.

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JQueryUI was designed especially for this.

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http://www.sencha.com/products/extjs/

ExtJS...

Here's an example "builder" app: http://www.projectspace.nl/