Enterprise interoperability is the emerging need in Europe for joint projects and business facing new marketing challenges.In multi-partner projects and business, aimed at developing innovative joint products, Large Enterprises suffer from a lack of synergy and cohesion with Medium-Small-Micro Enterprises due to the missing sharing of project information, flow of knowledge, synergy of workflows, etc. A novel level of integration is expected, while guaranteeing the security on proprietary information and preserving the already existing company management processes, fixed in years of past activity.The VENIS project is aimed at bridging the gap of interoperability between Large and Medium-Small-Micro Enterprises, according to the "Virtual Organisation" paradigm:-\ta distributed and secure repository to share the information contained in the file systems, databases, ERPs, CRMs, and other legacy applications of the enterprises, connecting the IT Infrastructures from Large to Micro enterprises;-\ta set of lightweight web services for the smart integration of the information exchanged in joint works, based on legacy email systems and boosted by semantic annotations and search;-\ta distributed processes engine mechanism, able to link and execute the enterprises business processes, to assist the work in joint businesses and to create novel synergies in products supply chains.Latest documents and multimedia, meeting planning, joint work flow and milestones, etc. will be then easily available to all the persons involved both from Large to Micro enterprises, while leaving almost unchanged the already existing legacy procedures.The Consortium, composed by 7 Partners skilled in international collaboration, is well balanced in expertise between technology developers and final users. The VENIS results will be disseminated on the Web and in International Conferences, thanks to the creation of a VENIS Community of users,Boosted by VENIS, the involved Enterprises expect to improve their competitive edge in joint projects, by exploiting the project results in their joint business and towards external market, bringing an estimated 15-20% increase of business during the 3 years following the end of the project.