A Large Scale Study of License Usage on GitHub

The open source community relies upon licensing in order to govern the distribution, modification, and reuse of existing code. These licenses evolve to better suit the requirements of the development communities and to cope with unaddressed or new legal issues. In this paper, we report the results of a large empirical study conducted over the change history of 16,221 open source Java projects mined from Git Hub. Our study investigates how licensing usage and adoption changes over a period of ten years. We consider both the distribution of license usage within projects of a rapidly growing forge and the extent that new versions of licenses are introduced in these projects.