Evolution of Volunteer Participation in Libre Software Projects: Evidence from Debian

Most libre software projects rely on the work of volunteers. Therefore, attracting people who contribute their time and technical skills is of paramount importance, both in technical and economic terms. This reliance on volunteers leads to some fundamental management challenges: volunteer contributions are inherently difficult to predict, plan and manage, especially in the case of large projects. In this paper we analyze the evolution in time of the human resources of one of the largest and most complex libre software projects composed primarily of volunteers, the Debian project. Debian currently has around 1300 volunteers working on several tasks: much activity is focused on packaging software applications and libraries, but there is also major work related to the maintenance of the infrastructure needed to sustain the development. We have performed a quantitative investigation of data from almost seven years, studying how volunteer involvement has affected the software...