FlowViewer is a set of three tools (FlowViewer, FlowGrapher, # FlowTracker) that create text reports, graph reports, and long-term tracking reports from flow-tools and SiLK captured and stored netflow data. FlowViewer can run with both flow-tools and SiLK simultaneously. Flow-tools can handle up to v7; SilK can handle v5, v9, and IPFIX.
Read more and download FlowViewer – http://sourceforge.net/projects/flowviewer/