Yes, Rendezvous is still going strong. Tonnes of deployments in FSI, Telco, Fabs, etc. That said its showing its age in the cloud among couple of other areas. We typically point users who need low latency data distribution to RV's successor called FTL. Similar peer to peer architecture like RV, but new capabilities like multi-transport (tcp/mcast/rdma/shared mem), content-selectors, pub-sub/req-reply semantics. And wicked fast on commodity hardware.

I haven't looked at Iris but the problem of abstracting physical from logical topology in distributed systems has been a major influence on RV and FTL architecture. Real world problem once you move beyond speeds and feeds and "looks ma, sockets!" semantics.