Best web UI framework for Visual-Studio-like layout management + component instantiation

Have a look at this screenshot of Visual Studio resizing / merging / instantiating new sub-panels in the main window: Visual Studio UI Framework

I'm trying to create a single page web application that is very similar to this - I want to be able to create new "panels" and drag/drop/group them into place. Ideally the framework should be as flexible as Visual Studio is.

Does anything like this exist or I will have to do everything myself ?

Thanks!