0MQ messaging
PHP Manual

Introduction

Warning

This extension is EXPERIMENTAL. The behaviour of this extension including the names of its functions and any other documentation surrounding this extension may change without notice in a future release of PHP. This extension should be used at your own risk.

"ØMQ is a software library that lets you quickly design and implement a fast message-based application." --0MQ Website

For more information about 0MQ, see » http://zeromq.org/.