Abstract
This paper delineates the main characteristics of the Episciences platform, an environment for overlay peer-reviewing that complements existing publication repositories, designed by the Centre pour la Communication Scientifique directe (CCSD) service unit. We describe the main characteristics of the platform and present the first experiment of launching two journals in the computer science domain onto it. Finally, we address a series of open questions related to the actual changes in editorial models (open submission, open peer-review, augmented publication) that such a platform is likely to raise, as well as some hints as to the underlying business model.