Free/Open Source Software (FOSS) development is not the same an Software Engineering (SE). Why this is so is unclear and open to various interpretations. Both address the challenges of developing large software systems, but the development processes, work practices, and project forms differ significantly and in interesting ways according to recent empirical studies. This paper reports on highlights from a workshop held in early 2010 on the future of research in FOSS, and how such research relates to or informs our understanding of FOSS and SE, collaborative software development work, software evolution, and new software ecosystems. FOSS and SE are complementary in many ways, yet different in others, so understanding these complements and differences can help advance the future of research in both FOSS and SE. Some of these complements and differences are identified in this paper. Categories and Subject Descriptors D.2 [Software Engineering]: software management, design methodology Gen...