Over the last decade, free and open source software (FOSS) has gradually become recognized by different actors in society outside FOSS communities and increasingly integrated in corporate software development, challenging proprietary software practices and establishing new open source companies. Literature describing this transition is focusing a narrow view on the value of using FOSS, mainly understanding it as an efficient alternative to established models for software development. This is not sufficient to fully understand the uptake of FOSS into companies. In order to gain a deeper understanding of this, there is a need to articulate a wider range of different values associated with FOSS and how they interplay in the intersection of corporations and movements. To do this we propose the order of worth framework developed by French sociologist Luc Boltanski and colleagues, which focus on the arrangements of value logics as an analytical strategy to understand how values form strong or weak arrangements in processes of institutionalization. By applying the framework on key texts from the free and open source software movement as well as on a an interview study with professional software developers employed by firms, we set out to identify how values associated with FOSS become justificatory arrangements that give legitimacy to FOSS and how these arrangements change over time, from the early free software movement to the emergent uptake of FOSS in contemporary professional software development. By understanding how justificatory logics come to play and interplay, corporations that want to adopt FOSS can better manage their engagement in FOSS activities. Keywords: Free and Open Source Software, Orders of Worth, Justification logics, Value of Open Source.