Changes in free and open source software licenses: managerial interventions and variations on project attractiveness

Abstract

The license adopted by an open source software is associated with its success in terms of attractiveness and maintenance of an active ecosystem of users, bug reporters, developers, and sponsors because what can and cannot be done with the software and its derivatives in terms of improvement and market distribution depends on legal terms there specified. By knowing this licensing effect through scientific publications and their experience, project managers became able to act strategically, loosening up the restrictions associated with their source code due to sponsor interests, for example; or the contrary, tightening restrictions up to guarantee source code openness, adhering to the “forever free” strategy. But, have project managers behaved strategically like that, changing their projects license? Up to this paper, we did not know if and what types of changes in these legal allowances project managers have made and, more importantly, whether such managerial interventions are associated with variations in intervened project attractiveness (i.e., related to their numbers of web hits, downloads and members). This paper accomplishes these two goals and demonstrates that: 1) managers of free and open source software projects do change the distribution rights of their source code through a change in the (group of) license(s) adopted; and 2) variations in attractiveness are associated with the strategic choice of a licensing schema. To reach these conclusions, a unique dataset of open source projects that have changed license was assembled in a comparative form, analyzing intervened projects over its monthly periods of different licenses. Based on a sample of more than 3500 active projects over 44 months obtained from the FLOSSmole repository of Sourceforge.net data, 756 projects that had changed their source code distribution allowances and restrictions were identified and analyzed. A dataset on these projects’ type of changes was assembled to enable a descriptive and exploratory analysis of the types of license interventions observed over a period of almost four years anchored on projects’ attractiveness. More than 35 types of interventions were detected. The results indicate that variations in attractiveness after a license intervention are not symmetric; that is, if a change from license schema A to B is beneficial to attractiveness, a change from B to A is not necessarily prejudicial. This and other interesting findings are discussed in detail. In general, the results here reported support the current literature knowledge that the restrictions imposed by the license on the source code distribution are associated with market success vis-a-vis project attractiveness, but they also suggest that the state-of-the-science is superficial in terms of what is known about why these differences in attractiveness can be observed. The complexity of the results indicates to free software managers that no licensing schema should be seen as the right one, and its choice should be carefully made, considering project strategic goals as perceived relevant to stakeholders of the application and its production. These conclusions create awareness of several limitations of our current knowledge, which are discussed along with guidelines to understand them deeper in future research endeavors.