Coordination without discussion? Socio-technical congruence and Stigmergy in Free and Open Source Software projects

The idea of congruence between the structure of technical and work dependencies has been demonstrated in commercial software development but has not been explored in detail in free and open source software (FLOSS) development. Previous work identified 103 task episodes, selected from two FLOSS projects, and found that 83 were performed by single actors. We analyze the 20 tasks with multiple actors and find that 14 were performed in the absense of any discursive communication between developers. The qualitative analysis of this evidence shows the paradox that, even if the developers do not seem to communicate explicitly, the software is nonetheless built as result of a collective effort, apparently without central coordination. In answer to this puzzle, this paper turns to the concept of stygmergic coordination as possible explanation. Stigmergy explains how actors can affect the behavior of other members of the community through the traces that their activities leave in shared artifacts. Such collaboration has implications for the socio-technical congruence analysis and the design of collaborative systems.