This is a clone of the GitHub green squares visualization - it's called Mrs. Green Squares. It works on your local repositories instead of the repos on GitHub. It only looks at commits on the master branch and you can specify which authors to include. It displays the full timeline instead of a single year.
Here is a full timeline of all my GitHub projects and here are all my git projects. Here is one where blue is client work and yellow is personal projects.
The visualization is generated with a Node.js script and the output format is HTML. The project date is July 2016.