JAMI (Java-based Agglutination of Medical Information) is designed as a framework for integrating heterogeneous information systems used in healthcare related institutions. It is one of the implementations under the W3-EMRS project 1 aimed at using the World Wide Web (Web) to unify different hospital information systems. JAMI inherited several design decisions from the first W3-EMRS implementation described in, including using the Web as the communication infrastructure and HL7 as the communication protocol between the heterogeneous systems and the W3-EMRS systems. In addition, JAMI incorporates the growing Java technologies and has a more flexible and efficient architecture. This paper describes JAMI's architecture and implementation. It also present two instances of JAMI, one for the integration of different hospital information systems and another for the integration of two heterogeneous systems within a single hospital. Some important issues for the further development of JAMI, including security and confidentiality, data input and decision support are discussed.