What are the similarities of open data and open source software when building a business? Despite their differences as phenomena (one is about applications and one is about data), the two also have many similarities. Both for example share the idea that the transparency of the artifact enables contribution. Many developers of open data have experience with open source development. But do the companies that build their offerings on open data and open source have similarities and if so, what are the similarities? Drawing on fieldwork and interviews with software entrepreneurs and managers, this paper investigates these questions through an empirical focus on openness in business and clarifies the links between commercial organizations engaged with open source and open data.