Experimental Node.js application that creates a DOT representation of a git repository.
DOT files can be used to create graphs with Graphviz.
Some image viewers you can easily open the results with: nomacs, feh, inkview (for svg, part of inkscape)
With intermediate files:
node index.js /path/to/some/repo/.git > repo.gv dot -Tsvg repo.gv -o repo.svg inkview repo.svg &
node index.js /path/to/some/repo/.git > repo.gv dot -Tpng repo.gv -o repo.png feh repo.png &
Example PNG: