Understanding and Auditing the Licensing of Open Source Software Distributions

Free and open source software (FOSS) is often distributed in binary packages, sometimes part of GNU/Linux operating system distributions, or part of products distributed/sold to users. FOSS creates great opportunities for users, developers and integrators, however it is important for them to understand the licensing requirements of any package they use. Determining the license of a package and assessing whether it depends on other software with incompatible licenses is not trivial. Although this task has been done in a labor intensive manner by software distributions, automatic tools to perform this analysis are highly desired. This paper proposes a method to understand licensing compatibility issues in software packages, and reports an empirical study aimed at auditing licensing issues in binary packages of the Fedora-12 GNU/Linux distribution. The objective of this study is (i) to understand how the license declared in packages is consistent with those of source code files, and (ii) to audit the licensing information of Fedora-12, highlighting cases of incompatibilities between dependent packages. The obtained results - supported by feedback received from Fedora contributors - show that there exist many nuances in determining the license of a binary package from its source code, as well as cases of license incompatibility issues due to package dependencies.