In this paper, we examine the identity of fablabs as representative of new forms of relations between science and society. Our empirical research was conducted in 7 fablabs that are open to the public and are operating or being set up in France. We characterized the fablabs, their users, their activities and their design process in each situation. We distinguish two types of fablab according to their organization and objectives. The first ones stem from initiatives by individuals or micro-groups, and their activities are essentially in the realm of a collaborative economy. Rather than providing a simple prototyping service, they seek to fill a “structural gap” in the innovation ecosystem through brokering and by promoting users and open innovation. The second ones are part of a national program run by science centers, aimed at promoting digital culture and practices among the youth. They differ from the former insofar as they are set up in an existing institution with a network of actors, which they disrupt. We examine how they challenge the business of public understanding of science as regards its practices and identities. Through exploration of the learning practices at stake in these fablabs, we call into question their appropriateness for open fablabs and the co-production of knowledge for lay people.