identifying groups

Hi everyone,
Does anyone know if there is a package to perform a  Moody's Crowds 
routine to identify groups using R, or other algorithms designed to 
search groups by maximizing modularity scores? Otherwise, other packages 
to identify groups, or other programs to do it.

I have about 80 networks clustered in schools. So, I have to identify 
groups for each school.

Thank  you in advance!

Sebasti?n Daza
sebastian.daza at gmail.com