I've used both Sigma.js and Arbor.js (http://arborjs.org/ http://arborjs.org/) extensively. I liked Arbor a bit better for smaller graphs, because of its flexib

I've used both Sigma.js and Arbor.js (http://arborjs.org/ http://arborjs.org/) extensively. I liked Arbor a bit better for smaller graphs, because of its flexible API and separated drawing and math components. Unfortunately Arbor seems abandoned by the author last updates were two years ago), so i guess Sigma might be a better choice right now.