Appears in collection : 6e Séminaire Itzykson : "Physique statistique hors équilibre"

During the last twenty years, a large number of exact solutions have been derived for some non-equilibrium interacting systems, such as the exclusion process, leading us to a better understanding of non-equilibrium behaviour. Integrability has played an important role in these developments. In this talk, we shall review some of the techniques involved and present a few representative results obtained in the field.