glasso:

Graphical lasso for R

Authors: Jerome Friedman, Trevor Hastie and Rob Tibshirani
Maintainer: Rob Tibshirani

This software, written in the R language, estimates a sparse inverse covariance matrix using a lasso (L1) penalty. It can be used for estimating a sparse undirected graph.
Version 1.3 fixed some errors in the Meinhausen-Buhlmann approximation, and includes a new function for computing the solution along a path of regularization parameters.

Based on the paper
Sparse inverse covariance estimation with the graphical lasso (Friedman, Hastie, Tibshirani, published in Biostatistics)


glasso R package (Linux gz file)
Windows and MAC versions available at CRAN