The Interface Definition Language (IDL) that accompanies CORBA-2.0 provides the constructs needed to specify interfaces only.

IDL allows for specifying modules, consisting of interfaces. An interface specification may contain (read only) attributes and operations. Operations are synchronous, unless annotated as oneway. Operations may raise exceptions upon failure.

Interface Definition Language

IDL

modules -- for clustering
interfaces -- correspond with objects
attributes -- may be read only
operations -- best effort invocation
exceptions -- for handling failure

Language bindings

C, Smalltalk, C++, Java

See www.infosys.tuwien.ac.at/Research/Corba/OMG

slide: Interface Definition Language -- IDL

Although IDL is syntactically very similar to C++ or Java, it completely lacks the algorithmic constructs of these languages. Objects specified in IDL must be realized in one of the languages for which an official IDL language binding exists, such as C, Smalltalk, C++ or Java, or an unofficial binding, such as Python, Perl and Prolog.