Nanomsg is next version of ZeroMQ lib, providing smart cross-platform sockets for implementation of distributed architectures. Here you can find basic examples of included protocols (communication patterns). Lib is simple (written in pure C) and does not have any dependencies like boost. And as this is at least 3rd iteration from same author you can expect some quality/performance here.
This is kind of solution for the hell of writing of your own serious socket server. If you already had such experience you should understand the range of problems which are not so obvious at start. But here we expect to skip all such problems and go straight to processing messages. Lib handles automatic reconnection in case of link disconnects, nonblocking receiving/sending, sockets which can handle large set of clients, etc. All this seems like perfect solution for server-side inner transport of fast distributed architectures.
But i also want to try it outside. The basic communication patterns (PAIR, BUS, REQREP, PUBSUB, PIPELINE, SURVEY) may fit large set of inner server transport schemes, but there are some minor limits in current implementation for client side application. I mean limits of protocols, not the lib itself.