whats CORBA for?

can anybody tell me what is the purpose of corba?
whats difference beteen corba and rmi and ejb?
what is middleware?
any practicle example where they can be used?
thank you
sachin

Hi Sachin
CORBA is an architecture.
It is basically a link to connect/communicate/interface application software running
on heterogenous platforms.
RMI also is an interface but it connects applications running on different servers but written totally in Java.
EJB again is an architecture and applications written using EJBs work on any system that supports the EJB specs.

Middleware, is a layer of software between the network and the applications. This software provides services such as identification, authentication, authorization, directories, and security.
Please correct me if I am wrong. Appreciate it.
Suneel

CORBA (Common Object Request Broker Architecture) is an architecture definition provided by Object Group.
RMI (Remote Method Invocation) is similar architecture provided by Java.

[This message has been edited by mibrahim (edited July 10, 2001).]

With Corba, u can have heterogenous platforms, for example
C++ client and java server. With RMI, both clients and server implementations are in Java. Further Corba interfaces are written
in IDL. For RMI, u can just write usual
Java interfaces.
[This message has been edited by Narayan Veeramani (edited July 10, 2001).]

The Common Object Request Broker Architecture (CORBA) from the Object Management Group (OMG) provides a platform-independent, language-independent architecture for writing distributed, object-oriented applications. CORBA objects can reside in the same process, on the same machine, down the hall, or across the planet.

Hi Sachin
According to me CORBA is specification and not technology.
This specification is implemented by many vendors.
[This message has been edited by Nakul Kasadwala (edited July 23, 2001).]

You can check out this for a comparison of CORBA RMI and DCOM.
Paul R