Good UI library / script to browse a web site using a graph?

I'm creating a set of web pages. I'd like to use a graph (visual nodes and edges) to navigate this website.

I plan to have a graph (a topic map) created from another software and exported in a suitable format. Each web page will be a node, and I'd like it to be able to display a thumbnail (at least some piece of text) whe开发者_StackOverflow中文版n hovering.

The graph should be force-directed, with pan/zoom capabilities, optionally hyperbolic. The graph is not a tree, each node may have an edge with any other.

I think about something in Javascript/Php/Java/Silverlight, but this is not a final choice.

Check out Protovis javascript visualization library from Stanford[1]. It has force-directed graphs.

An alternative the the Javascript infovis toolkit[2]. Check out the demos.

[1] http://vis.stanford.edu/protovis/

[2] http://thejit.org/