CORBA is the acronym for Common Object Request Broker Architecture, OMG's open, vendor-independent architecture and infrastructure that computer applications use to work together over networks. Using the standard protocol IIOP, a CORBA-based program from any vendor, on almost any computer, operating system, programming language, and network, can interoperate with a CORBA-based program from the same or another vendor, on almost any other computer, operating system, programming language, and network.
Some people think (or used to, when we originally wrote this page back in the early '90s) that CORBA is the only specification that OMG produces, or that the term "CORBA" covers all of the OMG specifications.