Update: ZeroMQ already mentioned above, sorry

ØMQ \zeromq\ looks like it could fit your bill. From their blurb at: zeromq.org:
 Ø  A socket library that acts as a concurrency framework.
 Ø  Faster than TCP, for clustered products and supercomputing.
 Ø  Carries messages across inproc, IPC, TCP, and multicast.
 Ø  Connect N-to-N via fanout, pubsub, pipeline, request-reply.
 Ø  Asynch I/O for scalable multicore message-passing apps.
 Ø  Large and active open source community.
 Ø  30+ languages including C, C++, Java, .NET, Python.
 Ø  Most OSes including Linux, Windows, OS X.
 Ø  LGPL free software with full commercial support from iMatix.

Note though, that they deliberately do not give 100% delivery guarantees. See their documentation why they choose this design and the ways your application can deal with it.