I came across this useful and interesting project so sharing with all of you:
Here is a very nice article that you may find useful
git has a very simple solution to see all the commits in a graphical form. If you need to understand all the commits history all you need is
git graphviz|dot -Tpng -o /tmp/a.png
This will generate a file called /tmp/a.png which will diplay the complete commit history.