We propose a new overlay network, called Generic Identifier Network (GIN), for collaborative nodes to share objects with transactions across affiliated organizations by merging the organizational local namespaces upon mutual agreement. Using local namespaces instead of a global namespace can avoid excessive dissemination of organizational information, reduce maintenance costs, and improve robustness against external security attacks. GIN can forward a query with an O(1) latency stretch with high probability and achieve high performance. In the absence of a complete distance map, its heuristic algorithms for self configuration are scalable and efficient. Routing tables are maintained using soft-state mechanisms for fault tolerance and adapting to performance updates of network distances. Thus, GIN has significant new advantages for building an efficient and scalable Distributed Hash Table for modern collaborative applications across organizations.