Most libre (free, open source) 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 chapter we present an analysis of the evolution over time of the human resources in large libre software projects, using the Debian project, one of the largest and most complex libre software projects based mainly in voluntary work, as a case study. We have performed a quantitative investigation of data corresponding to roughly seven years, studying how volunteer involvement has affected the software released by the project, and the developer community itself.
Michlmayr, M., Robles, G., Gonzalez-Barahona, J. M. (2007). Volunteers in Large Libre Software Projects: A Quantitative Analysis Over Time. In: Sowe, S. K., Stamelos, I. G., Samoladas, I. (Eds.), Emerging Free and Open Source Software Practices. 1–24.