In this article, a massive open online course (MOOC) made by and for Swedish teachers will be presented and discussed in order to determine what possibilities and dilemmas are involved when creating and participating in a MOOC that is meant to be a community rather than a course. By analysing interviews of the organisers as well as blog posts and surveys answered by participants, the conclusions that can be drawn point to the ambiguity of the boundary created between participating in a community and in a course. The way one is expected to participate in the MOOC differs from how one is usually expected to participate in professional development courses. The social aspects of a community become the focus for the participants in the MOOC rather than the content that it is addressing. The skeletal structure of the MOOC inhibits the participation of those who are unaccustomed to the digital environment where it takes place. Furthermore, the division of labour between participants and organisers is affected by the notion of course and therefore becomes ambiguous and creates tensions for both organisers and participants.