A virtual enterprise is a network of independent companies or departments, working together for a limited period of time on a specific project. The partners of a virtual enterprise co-operate and co-ordinate by sharing data on their networked computers. Key issues in such a data sharing setting are persistence, distribution, concurrency, consistency, security and scalability. Existing systems do not provide acceptable solutions. They do not only provide just partial solutions, they are additionally complex to use, lacking performance and are not easy to integrate in existing applications. The PERDIS project provides an integrated, complete and elegant alternative solution. PERDIS provides application programmers with automatic and transparent data persistence and distribution. It allows concurrent data access while keeping it globally coherent. Access to shared data is controlled by access rights and data communication is encrypted. PERDIS supports large scale applications and its application programmer interface is simple and easy to use. PERDIS targets co-operative engineering applications in virtual enterprises. A typical application domain is the building and construction industry where geographically scattered co-operative teams share a large number of highly connected data objects during concurrent and possibly long working sessions. Currently, implementations for different architectures are available and several existing computer aided design (CAD) applications are being ported.