PHP bindings for 0MQ. The documentation is available at http://php.net/zmq

The API is roughly as follows:

<?php

/* Create new queue object */
$queue = new ZMQSocket(new ZMQContext(), ZMQ::SOCKET_REQ, "MySock1");

/* Connect to an endpoint */
$queue->connect("tcp://127.0.0.1:5555");

/* send and receive */
var_dump($queue->send("hello there, using socket 1")->recv());

?>

For installation instructions see http://pecl.php.net/zmq