Although not strictly for forensic purposes, visualization tools such as the ones discussed here can be very useful for visualizing large data sets. As forensic practitioners need to process more and more data, it is likely that some of the techniques implemented by these tools will need to be adopted.

Open Source Visualization Toolkits

The Visualization Toolkit: C++ multi-platform with interfaces available for Tcl/Tk, Java and Python. Professional support provided by Kitware.

Graphviz: Originally developed by the AT&T Information Visualization Gorup, designed for drawing connected graphs of nodes and edges. Neato is a similar system but does layout based on a spring model. Can produce output as PostScript, PNG, GIF, or as an annotated graph file with the locations of all of the objects---ideal for drawing in a GUI. Runs from the command line on Unix, Windows and Mac, although there is also a MacOS GUI version.

OpenDX: Based on IBM's Visualization Data Explorer, runs on Unix/X11/Motif.

VisAD: A Java component library for interactive and collaborative visualization.

Graph Drawing Tools

uDrawGraph

Commercial Tools

aiSee Graph Layout Software: Supports 15 layout algorithms, recursive graph nesting, and easy printing. Runs on Windows, Linux, Solaris, NetBSD, and MacOS. 30-day trial and free registered versions available. Academic pricing available.

Tom Sawyer Software Analysis, Visualizaiton, and Layout programs.: Heavy support for drawing graphs. Beautiful gallery. ActiveX, Java, C++ and .NET editions.