Background: The adoption of Free/Libre and Open Source Software (FOSS) by institutions is significantly increasing, and so is the affiliated participation (the participation of industry engineers in open source communities as part of their jobs). Aims: This study is an investigation into affiliated participation in FOSS communities. So far, little is known about the affiliated participation and the forces that influence it, even though the FOSS innovation model is increasingly becoming a serious contender for the private investment model in many sectors. Method: We present a qualitative inquiry into affiliated participation in the Robot Operating System (ROS) and Linux Kernel communities, using twenty-one in-depth interviews and participatory observation data from twenty-nine community events. Results: Our results show that affiliated participation in these communities is constrained by several barriers: objections of senior management, protection of the company’s image, protection of intellectual property, undefined processes and policies, the high cost of participation, and unfamiliarity with the FOSS system. Conclusions: These barriers should be addressed in any organization considering using FOSS as a significant acquisition, distribution, and development strategy.