Impact of license choice on Open Source Software development activity

The Open Source Software (OSS) development model has emerged as an important competing paradigm to proprietary alternatives; however, insufficient research exists to understand the influence of some OSS project characteristics on the level of activity of the development process. A basic such characteristic is the selection of the project's software license. Drawing upon social movement theory, our study examined the relationship between OSS licenses and project activity. Some OSS licenses include a “copyleft” clause, which requires that if derivative products are to be released, it must be done under the license the original product had. We hypothesize that copylefted licenses, as opposed to noncopylefted licenses, are associated with higher developer membership and coding activity, faster development speed, and longer developer permanence in the project. To test the hypotheses, we used archival data sources of working OSS projects spanning several years of development time. We discuss practical and theoretical implications of the results as well as future research ideas. © 2009 Wiley Periodicals, Inc.