In 2009, Andrew Caudwell started the Gource project (GPL 3.0), an application for visualizing changes in a project based on version control system data (Git, Mercurial, SVN). https://gource.io

(124MB video)

Gource shows the project repository as an animated tree, with the root directory in the center. Dots represent individual files and sub-directories. Authors appear and disappear as they make changes. https://github.com/acaudwell/Gource

Support for Gravatar (a database of avatars associated with an email address) looks interesting. https://github.com/acaudwell/Gource/wiki