Over the last 20 years, open-source development has become an integral part of the software industry. Against this backdrop, this article seeks to develop a systematic overview of open-source communities and their socio-economic contexts. I begin with a reconstruction of the genesis of open-source software projects and their changing relationships to established information technology companies. This is followed by the identification of four ideal-type variants of current open-source projects that differ significantly in their modes of coordination and the degree of corporate involvement. Further, I examine why open-source projects lost their subversive connotations while, in contrast to former cases of collective invention, remaining viable beyond the initial phase of innovation.