It has been lately established that a major success or failure factor of an OSS project is whether or not it involves a commercial company, or more extremely, when a project is managed by a commercial software corporation. As documented recently, the success of the Eclipse project can be largely attributed to IBM’s project management, since the upper part of the developer hierarchy is dominated by its staff. This paper reports on the study of the evolution of three different Open Source (OSS) projects — the Eclipse and jEdit IDEs and the Moodle e-learning system — looking at whether they have benefited from the contribution of commercial companies. With the involvement of commercial companies, it is found that OSS projects achieve sustained productivity, increasing amounts of output produced and intake of new developers. It is also found that individual and commercial contributions show similar stages: developer intake, learning effect, sustained contributions and, finally, abandonment of the project. This preliminary evidence suggests that a major success factor for OSS is the involvement of a commercial company, or more radically, when project management is in hands of a commercial entity.