This data is just draft. The data was gathered by scraping the ViewVC output on source.sakaiproject.org. If you find anomalies in the data contact Dr.Chuck. The vertical axis is commits in the particular quarter and the horizontal access is cumulative commits. This does not include tag commits. This is probably a better indication of the long-term consistency of contributions and number of staff dedicated to working on the Sakai code base rather than the importance or complexity of the contributions.
Hints: (1) Change from "Same Color" to "Unique Colors", (2) Change from "Same Size" to "Cumulative", and (3) Experiment switching from Linear to Log scale to make it more exciting, (4) hover over a data point to see who it represents, and (5) you can click on a data point to make it have a "trail".