Web Window Manager (UI Framework)

I'm interested in putting together a web framework to emulate a desktop-like window manager. If you're asking why; the reason is that I want to create a web application that has the capabilities and look-and-feel of a desktop application, yet be portable across multiple platforms and without installing software. I'll most likely be doing this is JavaScript, possibly with the aid of jQuery. I just wanted to gauge some opinions prior to building it.

Generally, what features and/or behavior do you expect from your ideal window manager? Also, is a task like this most suited for a canvas-based implementation or a HTML element implementation?

I know there are some other options out there, but I want to create a pretty comprehensive API as a sort of gateway project. Are there any existing proj开发者_开发知识库ects that come into mind? I know jQuery-UI is pretty popular, and I've used it occasionally.

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I am in the same position as the OP and am interested in seeing some actual responses and not criticisms of the question. There are a lot of different frameworks out there and given limited time it's not an easy thing to research.

Of course there is a concise way to answer this question: "I chose (framework X) for my last project because (reason A), (reason B), etc. and eliminated (framework Y) because (reason C)"

It's not wheel reinvention - the question is about wheel SELECTION.

I'll also add this:

jquery & plugins is great based on my experience with jquery but suffers from unified look and feel due to there not being a single library of UI plugins.

GWT is a front-runner for me right now as I'm going to use Glassfish/Java as my app server, and I'm trying to figure out how well it supports tablet clients.

Sencha/ExtJS has what I'm looking for from the perspective of all the components, but if I'm going to spend the money to get a commercial product I'd rather purchase one from adobe (AIR) or another big company that I know will be around for a longer time. I'm also concerned over the amount of structure that Sencha's proprietary MVC will constrain me to on the app server - it probably will cause me a lot of work to develop around it.

Dojo is also promising, I'm researching that further.