ZMQ extension requires 0MQ version 2.0.7 or higher. 0MQ can be acquired from » http://zeromq.org/area:download.
Information for installing this PECL extension may be found in the manual chapter titled Installation of PECL extensions. Additional information such as new releases, downloads, source files, maintainer information, and a CHANGELOG, can be located here: » http://pecl.php.net/package/zmq