On his blog Sebastian Bergmann has a recent post about how he's visualizing PHPUnit's development and pushing that information into a video based on the history of the project.
According to svn.php.net, I committed the first PHPUnit code to cvs.php.net on November 27th 2001 and the first release, PHPUnit 0.1, was made on December 1st 2001. [...] On December 26th 2009, I moved the development of PHPUnit from svn.phpunit.de to GitHub. I imported the history from Subversion into Git. As you can see in the video, moving to GitHub lead to an increased number of contributions to PHPUnit.
You can watch the video either embedded in his post or directly from Vimeo. It's interesting to watch the progress of the application and see the contributions make to each of the parts. The whole video, spanning the entire commit history of the tool, lasts about 25 minutes.