UCINET - UCINET for Windows is a software package for the analysis of social network data.
JFLAP - JFLAP is software for experimenting with formal languages topics including nondeterministic finite...
Gephi - Gephi is an open-source software for visualizing and analyzing large networks graphs.
GraphThing - GraphThing is a tool that allows you to create, manipulate and study graphs.
Graphviz - Graphviz is open source graph visualization software. It has several main graph layout programs.
Pajek - Pajek is a lightweight solution developed from scratch by an extraordinary team of developers for the purpose of Large Network Analysis.