RDF GRAph VIsualization Tool (RDF Gravity) is a tool for visualizing directed graphs built in RDF and OWL. The tool provides a simple yet powerful visualization of RDF graph structures and the ability to filter out and visualize specific parts or fragments of RDF Graphs.
"GUESS is an exploratory data analysis and visualization tool for graphs and networks... contains a domain-specific embedded language called Gython (an extension of ... Jython) which supports the operators and syntactic sugar necessary for working on grap
S. Havre, B. Hetzler, and L. Nowell. INFOVIS '00: Proceedings of the IEEE Symposium on Information Vizualization 2000, page 115. Washington, DC, USA, IEEE Computer Society, (2000)