ØMQ

ØMQ (ZeroMQ, 0MQ, zmq) looks like an embeddable networking library but acts like a concurrency framework. It gives you sockets that carry whole messages across various transports like in-process, inter-process, TCP, and multicast. You can connect sockets N-to-N with patterns like fanout, pub-sub, task distribution, and request-reply. It's fast enough to be the fabric for clustered products. Its asynchronous I/O model gives you scalable multicore applications, built as asynchronous message-processing tasks. It has a score of language APIs and runs on most operating systems. ØMQ is from iMatix and is LGPL open source.

Quotes

	The best way to get started with ZeroMQ is to work through some hands-on examples - the concepts are not new, but the ease with which you can compose them takes some getting use to.
	— Ilya Grigorik

	0MQ sockets being asynchronous means that the timings of the physical connection setup and teardown, reconnect and effective delivery are transparent to the user and organized by 0MQ itself. Further, messages may be queued in the event that a peer is unavailable to receive them.
	— Brian Buchanan

	The more time I spend with ZeroMQ, the less I can think of a reason I'd ever have to open up a raw TCP or UDP socket, except in extraordinary circumstances, again.
	— Andrew Cholakian

	0MQ ("Zero-Em-Queue") is a messaging system that tackles these issues by taking a different approach. Instead of inventing new APIs and complex wire protocols, 0MQ extends the socket API, eliminating the learning curve and allowing a network programmer to master it in a couple of hours. The wire protocols are simplistic, even trivial. Performance matches and often exceeds that of raw sockets.
	— Martin Lucina and Martin Sustrik

	ZeroMQ is a messaging library, which allows you to design a complex communication system without much effort.
	— Nicholas Piël

	What ZeroMQ does is create an API that looks a lot like sockets, and feels the same, but gives you the messaging styles you actually want. By simply specifying the type of socket when you call zmq_socket you can have multicast, request/reply, and many other styles.
	— Zed Shaw

See also

• ZeroMQ official site
• Foundation ontology