Gource-analytics is a project mainly written in Python, it's free.
This is the Google Analytics visualization script for Gource
This is the script used to convert Google Analytics data into Gource visualization.
See http://pyevolve.sourceforge.net/wordpress/?p=1423 for more information.
Sample video at http://www.youtube.com/watch?feature=player_embedded&v=NEXB37XvryE