Side-by-side-, diff-, and animation-based visualizations for request-flow comparison, as described in the InfoVis'13 paper "Visualizing Request-flow Comparison to Aid Diagnosis in Distributed Systems." Project documentation is in doc/index.html.
Getting started quickly: open index.html in a browser (tested with Chrome 34).
Using your own graphs: see the "Generating Graphs" section in the project documentation (doc/index.html).