With the interrest for OGC Web Processing Service growing, we need to know details about the Open Source Solutions available. Various projects implementing WPS designed individuals from their community to participate in this talk to introduce their project and summarize their key features, they are the following: 52¡North WPS, Constellation SDI, GeoServer, PyWPS, ZOO-Project. For being able to provide good quality results, the tests should be run locally, so a server dedicated to this WPS Benchmarking Session, hosting OSGeoLive environments, is accessible to each team for running test procedures defined through discussions. The results of the given test procedures will be presented during this session and will compare implementations from different aspects: capabilities, compliancy, ressources usage and performance.