A First Look at Commit Data for an Open Source Software Project

I got a little something to sink my teeth into. I am looking at commit data for some open source projects. This is mostly an exercise in regaining my sql chops and learning R. Here is my first plot:

The plot has the alias of the submitter along the X and the timestamp along the Y. What you can see for this one project is that there are two heavily dedicated submitters who both started working on the project about the same time, one who is more sporadic and started shortly before the two of them and two who appear to have started the project but only periodically commit although their activity is relatively consistent over the entire length of the project. What is somewhat surprising is how many there are who have almost no commit activity (there is some doubt regarding whether this alias is the submitter or committer although it is supposed to be the commit id). It seems odd that someone would have gained committer status and then stopped commiting. Will I see this pattern in other projects? Who are these heavy committers and how do they differ in role from the people who appear to have started the project?