R: a free software environment for statistical computing and graphics.
UCINET: Windows software for analyzing social network data.
Pajek: A program for large network analysis, free for noncommercial use.
SoNIA (Social Network Image Animator): A Java-based package for visualizing dynamic or longitudinal “network” data.
SIENA (Simulation Investigation for Empirical Network Analysis)
Statnet: R-based software tools for the analysis, simulation, and visualization of network data.
SNAP (Stanford Network Analysis Platform): A general purpose, high performance system for analysis and manipulation of large networks.
R video tutorials created by the Odum Institute.
Hanneman, Robert A. and Mark Riddle. 2005. Introduction to social network methods. Riverside, CA: University of California, Riverside. Link to on-line textbook:(http://faculty.ucr.edu/~hanneman/nettext/)