SourceForge is highly helpful in developing free applications
SourceForge is a web site for managing open source application. What strikes me most about it is the transparency it brings including the statistics. You can see how many downloads and page views the project has and had, together with all the history of activity, that all compared to other projects. You can see what kind of applications are found useful by users, and you can estimate the cash contribution your project is making on the global scale, thus controlling at least a bit if the activity of development is economical in terms of value.
Unlike commercial projects, free projects have hard time measuring the contribution and efficiency of consumed resources like time and concentration of their developers. Some economic mathematical model should be developed to enable estimation of contribution of such projects, provided that their developers want to create value rather than just have a good time, the two not being necessarily at cross-purposes.