Interoperability and interchangeability of middleware components in a three-tier CORBA-environment-state of the art

The paper covers heterogeneous multi-tier environments based on CORBA and Java. On the client side there is a Web browser that connects to the middle tier through CORBA-based Java applets. The business logic is decoupled from the database server on the third tier. Access to the databases is made through a JDBC interface or with embedded SQL. We present considerations about the use of different browsers and multiple ORBs, concentrating on interoperability issues. We explore the problems that have to be faced and give practical advice on how to make things work.