TIBCO Rendezvous is a software product that provides a message bus for enterprise application integration (EAI).
The basic message passing is conceptually simple: Considerable "Enterprise" functionality is layered onto this if desired with Fault Tolerance/Reliable or Certified options possible, all implemented through the underlying basic messages.
The quality of the respective API implementations varies considerably.
The C++ library is simply a wrapper providing an OO view over the C implementation.
This has led to memory management issues with the .NET implementation (though not with the COM Interop version which is considerably more cumbersome).