[asutherland]

viz.js (https://github.com/mdaines/viz.js demo at http://viz-js.com/) is graphviz compiled to JS using emscripten. graphviz-d3-renderer (https://github.com/mstefaniuk/graph-viz-d3-js demo at http://graphviz.it/) uses viz.js to render to (x)dot format, then parse that so you can use d3 on top of it. Using those two, you should be able to leverage the layout smarts of graphviz with the presentation smarts of d3.