The comment density of open source software code

The development processes of open source software are different from traditional closed source development processes. Still, open source software is frequently of high quality. Thus, we are investigating how open source software creates high quality and whether it can maintain this quality for ever larger project sizes. In this paper, we look at one particular quality indicator, the density of comments in open source software code. In a large-scale study of more than 5,000 projects, we find that active open source projects document their source code, and we find that the comment density is independent of team and project size, but not of project age. In future work, we intend to correlate comment density with project success or failure.