It is common to hear that DCE achieved
true interoperability in 1992 with DCE 1.0, while CORBA
interoperability was only recently specified and has yet to be delivered. Typically, each vendor ports
DCE
to a specific platform, and interoperability with the reference implementation ensures interoperability
among
vendors’ implementations.
OMG does not deliver reference
implementations, only specifications. CORBA 1.0 did not address
interoperability between ORBs because it was considered premature pending experience implementing basic
ORB functions. As a result, many vendors implemented ORBs on a selection of platforms, providing
interoperability across all of the platforms supported by a given vendor. In fact, some of the ORBs
that are
currently available run on over a dozen different platforms and support interoperable clients and servers
across all of those platforms at this time.
Interoperability between ORBs (that
is, between ORB vendors) will be a reality in 1995. The Internet Inter-
ORB Protocol (IIOP) specified by OMG in December of 1994 [CORBA2] may be supported via bridges that
can be developed by end-users or third parties without proprietary information about an ORB or
modifications to the ORB. In addition, SunSoft recently made available on the OMG server a public domain
implementation of the major components needed to implement an IIOP bridge. We therefore expect to see
widespread interoperability among ORBs via IIOP by late 1995 or early 1996. We expect this even with
ORBs that use DCE for intra-ORB communication, although interoperation between DCE-based ORBs may
be provided via a DCE-specific protocol specified by OMG as well.
1.Introduction
