The OpenPaaS project aims at developing an Open-Source Enterprise Social Network that leverage OBM collaborative solution and Petals BPM workflow engine and run-time. Leaded by LINAGORA, the French Open-Source Software leader, OpenPaaS addresses the whole collaborative application life-cycle. It provides basic features such as profile definition, collaborative mail, agenda, forms and workflow editors as well as an open API for external contributors. OpenPaaS’s run-time reuses Petals BPEL process engine and Petals Enterprise Service Bus. These tools are deployed on an hybrid IaaS infrastructure that allows to connect heterogeneous external applications. OpenPaaS project is funded by the FSN (Fond National pour la Société Numérique).