Gephi

Gephi is an interactive visualisation and exploration platform for all kinds of networks and complex systems, dynamic and hierarchical graphs.

• Runs on Windows, Linux and Mac OS X.
• Open-source and free.
• One of the (very) few projects of its kind that has not been dead for years
• Can extract MediaWiki data into .dot format with Graphical Category Browser extension

http://gephi.org/wp-content/gallery/screenshots/preview3.png

Features

• Real-time
• Customisable layout algorithms
• Metrics
• Dynamic network analysis and filtering
• Cartographic and geolocation graphs
• Clustering and hierarchical graphs

See also

• Mind map
• Prefuse