One important feature for the current and next generation of information systemsis the ability to be able tocooperate. Information systems that are able to cooperateare referred to as cooperative information systems. The problem of moving the stateof the art from information systems designed asislands of automationto cooperativeinformation systems has primarly been addressed by the distributed artificial intelli-gence community and the database community. For example, the distributed artificialintelligence community has investigated cooperation strategies such as task sharingand result sharing, whereas the database community has developed techniques forinteroperability over heterogenous databases. One characteristic of cooperative infor-mation systems is that no individual solution can satisfactorily support all requiredcharacteristics of cooperative information systems. This thesis takes the position thata synthesis of results from the distributedartificial intelligence community and thedatabase community is a promising direction for developing cooperative informationsystems.In this thesis, active capability (as defined within active databases) is considered asan important core technology for cooperative information systems. Active capabilityis supported by event condition action (ECA) rules with the following semantics:when an event E occurs, evaluate condition C, and if the condition is satisfied, thenexecute action A. The applicability of using ECA rules has primarly been exploredwithin database systems and has recently initiated ECA related research within otherresearch communities such as real-time and workflow.This thesis focuses on what is required in an interface between information sys-tems when using an active capability approach to supporting the major cooperationstrategies as formulated in distributed artificial intelligence. The significance of the2work reported in this thesis concerns two major issues. First, advanced types ofcooperation strategies such as task sharing and result sharing can now span the do-mains of database and distributed artificial intelligence architectures. Second, as thiswork synthesizes and extends results from two different research communities, it pro-vides a good foundation for using active capability as one of the core technologies forcooperative information systems.