This chapter tackles the issue of the distribution of work in an open source project through the influence of social relationships among developers. The author demonstrates that the concentration of code in the VideoLAN project —already pointed out in other projects—does not only depend on technical expertise but is strongly influenced by the nature of social relationships among developers. Face-to-face relationships have a great importance, as does friendship which can favor the circulation of advice. In addition to technical expertise, a second kind of expertise —the ability to be aware of who is working on what—determines the hierarchy within this entity that looks like a collegial organization. The author hopes that this work will help to reduce the hiatus between technical and social considerations on open source software.