Network Analysis Package for R
xUCINET is an R package for social network analysis which is meant to accompany by the book by Borgatti et al on Analyzing Social Networks Using R. At the moment, it is not available through Cran or GitHub, but can be installed via the instructions below.
The package is written and maintained by Filip Agneessens.
Note that in various places it makes use of several other packages, including sna, ergm, blockmodeling, and igraph.
To install the package, follow these instructions.