The CORBA (Common Object Request Broker Architecture) implementation in the Java platform provides standards-based interoperability and connectivity. Java IDL enables distributed Web-enabled Java applications to transparently invoke operations on remote network services using the industry standard OMG IDL (Object Management Group Interface Definition Language) and IIOP (Internet Inter-ORB Protocol).
Note to CORBA Developers:
Java IDL technology is for CORBA programmers who want to program in the Java programming language based on interfaces defined in CORBA Interface Definition Language (IDL). This is "business as usual" CORBA programming, supporting Java technology in exactly the same way as other languages such as C++ or COBOL.
Java SE CORBA Documentation: J2SE 1.4.2 | J2SE 5.0 | Java SE 6
In addtion to Java IDL, Java SE also supports Java Remote Method Invocation over Internet Inter-ORB Protocol technology ("RMI-IIOP") This technology provides the ability to write CORBA applications for the Java platform without learning CORBA Interface Definition Language (IDL).
Java RMI-IIOP Documentation: J2SE 1.4.2 | J2SE 5.0 | Java SE 6
RMI over IIOP is based on two specifications of the Object Management Group: