ohloh.net is a service that analyses the source code of open source projects and creates statistics.
Click on this button to see the statictics for the SharpDevelop repository:
All information on that page was automatically created by the service by looking at the subversion repository. It is wrong on the following points:
On the contributors page, you can see activity graphs for the individual developers. And you can see the comment ratio, which unfortunately is quite low (far below C# average according to the "Factoids"), but other popular open source projects like Firefox, OpenOffice or MediaWiki seem to have the same problem.