Turns out MICO has a C interface :) So I'm going to develop for MICO since:
a) MICO supports CORBA 2.2. The CORBA 2.2 API is well-defined in the spec
(as opposed to the rather vague 2.0 API)
b) MICO is a *complete* implementation.
c) I don't want to download the whole of GNOME to get ORBit out of it.
Taral