: Christopher VendomeVenue
: International Conference on Software EngineeringDate
: 2015Type of Experiement
: Case StudySample Size
: 16221Class/Experience Level
: Undergraduate Student, Graduate Student, ProfessionalParticipant Selection
: Open source Java projects mined from GitHubData Collection Method
This paper addresses the evolution of licenses in open source projects as development communities and new legal issues continue to arise. It reports the results of a large empirical study issued over the development history of 16,221 open source Java projects found on GitHub. The study aims to describe license usage and adoption over the course of ten years to explain a pattern of interaction between licenses.
There were two parts to identifying and classifying licenses. First, the study used MARKOS code analyzer to extract licenses of individual files by commits. Then, the data from each project was compiled and analyzed to class licenses by version number and commit date. Next, the study depicted the relative usage of licenses per year and compared how new versions of licenses dominated previous versions. The results of the study demonstrate how the open source community benefit strongly from licenses that offer more legal protection, yet are still permissive. For example, the Apache v2 license was widely used because it granted the original author patent protection.