The last version of the HCGene R source package is downloadable from:
http://homes.dsi.unimi.it/valenti/SW/hcgene/download/hcgene_1.0.1.tar.gz
To install the package on a unix/linux R environment, login as root and type from your shell prompt:
> R CMD INSTALL hcgene_1.0.1.tar.gz
This automatically installs the code and the HTML/pdf documentation. Note that HCGene requires the installation of several Bioconductor R packages: GO, GOstats, graph, Rgraphviz. In particular, the installation of the Bioconductor package Rgraphviz requires the installation of the library graphviz: http://www.graphviz.org
The HCGene reference manual in pdf format included in the package may be also downloaded from http://homes.dsi.unimi.it/valenti/SW/hcgene/doc/hcgene-manual.pdf