A system for generating user availability information to a subscriber from availability rules set by the user, comprising a shared database (e.g. tuple space), a user interface for setting availability rules with fuzzy indicators of degrees of user availability, and an application level for receiving and posting a request from the subscriber for user availability information to the shared database such that predetermined ones of the availability rules post responses to the shared database, computing from these responses a crisp indication of user availability information, and transmitting the crisp indication of user availability to the subscriber.