The theatrical job market is characterized by its extreme fragmentation. For a vast majority of professionals in the world of theatre, the possibility of accumulating resources depends on membership of networks which guarantee the same conventions. But, more than in other artistic spheres, for a minority which is often very soundly integrated, membership of these networks is accompanied by the constitution of stable collectives of production. First, there exist cores of highly organized professionals in independent companies, whose activity is constant and multiform. Second, loose networks of relations structure constant exchanges between professionals of a few companies which are economically and aesthetically close.