Network packages in R
Web Links

There are a number of other packages in R to perform structural/social network analysis.
  Web Link
  Link   RSiena
The R version of Siena is called RSiena and is available through CRAN: install.packages("RSiena")
  Link   SNA by Carter Butts
This is an extensive package written by Carter Butts. It includes the most common network metrics.
  Link   Statnet and ERGM
These are two packages used to visualization, analysis and simulation of social network data and calculate Exponential Random Graph Models (ERGM's) in R. It is created by the Center for Studies in Demography and Ecology at University of Washington.