The open source software movement is traditionally not affiliated to profit-oriented business behaviour. However, commercial activity has become increasingly common, and, business models have institutionalized in the field of open source software. The aim of this research paper is to explore the determinants of profitable revenue models for businesses based on open source software. Therefore, the study focuses on analysing different revenue options of open source software businesses as a part of more comprehensive open source software (OSS) business models. We explore other business model elements as the potential determinants of firm-level revenue model choices. This study draws on a qualitative research approach on the issue through two analytical business cases – MySQL and Red Hat – both of which illustrate the complexity and heterogeneity of solutions and options in the field of OSS. Thus, we analyse the business models of the selected case companies and identify the underlying endogenous elements, i.e. offerings, resources and relationships within them. Finally, we discuss the managerial implications derived from the cases to describe how these business model elements affect the development of successful revenue models in the field of open source software.