http://sigmajs.org/
http://cytoscape.github.com/cytoscapeweb/
I'd like to take a look at the "glue" code if so. I'm trying to
abstract some of these patterns into the d3.graph plugin:
http://en.wikipedia.org/wiki/Hypergraph
http://mathoverflow.net/questions/13750/what-are-the-applications-of-hypergraphs