The phenomenon of open source software has lately caught the attention of both the popular press and many researchers in such diverse fields as MIS, computer science, sociology, and management. The organizational challenges faced by open source development projects are significant, because a project must deal with the complexity of coordinating the efforts of a geographically distributed base of volunteers to create a working software product. Based on a theoretical framework of network governance, the influence of social mechanisms on the coordination and safeguarding of exchanges among project members, and how these influence project success are examined. Using survey and objective data, 38 open source projects are empirically investigated to test a formal path model of network governance in open source projects. The model of network governance provides a good explanation of how governance mechanisms can influence success in open source projects, namely, restricted access to the development team improves coordination within the project and safeguards exchanges among project members. Further, collective sanctions safeguard exchanges among project members, and the importance of reputation to project members aids in managing conflicts within the project. Finally, better coordination allows a project to be more successful, while safeguarding exchanges does not appear to impact project success.