Patch Review Processes in Open Source Software Development Communities: A Comparative Case Study

In spite of the overwhelming success of free/open source software (F/OSS) like Apache and GNU/Linux, there is a limited understanding of the processes and methodologies that specify this form of software development. In this paper, we examine the process of patch reviews as a proxy for the extent of code-review in F/OSS projects. While existing descriptions of patch review processes are mostly narrative and based on individual experiences, we systematically analyze the email archives of five F/OSS projects to characterize this process. While doing so, we make a distinction between contributions (patches or review comments) by core members and casual contributors to grasp the role of core members in this process. Our results show that while the patch review processes are not exactly identical across various F/OSS projects, the core members across all projects play the vital role of gate-keepers to ensure a high level of review for submitted patches