The Role of Participation Architecture in Growing Sponsored Open Source Communities Joel West San Jose State University, College of Business http://www.JoelWest.org/Research/OpenSource/ Siobhán O’Mahony UC Davis, Graduate School of Management Final manuscript draft February 6, 2008 Published as Joel West and Siobhán O’Mahony, “The Role of Participation Architecture in Growing Sponsored Open Source Communities,” Industry & Innovation, 15, 2 (April 2008): 145-168. http://dx.doi.org/10.1080/13662710801970142 Copyright: This is a preprint of an article whose final and definitive form will be © 2008 Taylor and Francis, and will be published in Industry & Innovation, which is available online at: http://journalsonline.tandf.co.uk/. Acknowledgements: Earlier versions of this paper were presented at the Academy of Management and European Academy of Management conferences. We thank the guest editors, two anonymous reviewers and especially the EURAM participants for their helpful suggestions. Abstract: Most research on open source software communities has focused on those that are community founded. More recently, firms have founded their own open source communities. How do sponsored open source communities differ from their autonomous counterparts? With comparative examination of 12 open source projects initiated by corporate sponsors, we identify three design parameters that together help form a participation architecture – the opportunity structure extended to potential external contributors. In exploring sponsors’ community design decisions, we found that sponsored open source projects were more likely to offer transparency than they were accessibility and that this had implications for their communities’ growth. We contribute theoretical constructs that offer a common basis of comparison for the future study of open source projects and illustrate how the tension between control and growth affects open source community design and creation.