The success of free software and open source projects has increased interest in utilizing the open source model for mature software development. However, the ad hoc nature of open source development may result in poor quality software or failures for a number of volunteer projects. In this paper, projects from SourceForge are assessed to test the hypothesis that there is a relationship between process maturity and the success of free software and open source projects. This study addresses the question of whether the maturity of particular software processes differs in successful and unsuccessful projects. Processes are identified that are key factors in successful free software projects. The insights gained from this study can be applied as to improve the software process used by free software projects.