Git_repository_viewer is a project mainly written in JAVASCRIPT and PHP, it's free.
A simple git repository viewer for Drupal
The Git Repository Viewer is a repository browser for Drupal that integrates with the versioncontrol suite of modules to provide an intuitive repository browser for Drupal.
It is currently under active development and is currently unstable. Feel free to download it and try it out.
git show 'commit'
)