The 'ZMQ::LibZMQ4' module is a wrapper of the 0MQ message passing library
for Perl.

Before you start using this module, please make sure you have read and
understood the zguide.

http://zguide.zeromq.org/page:all

For specifics on each function, please refer to their documentation for the
definitive explanation of each.

http://api.zeromq.org/

This module is merely a thin wrapper around the C API: You need to
understand how the C API works in order to properly use this module.

Note that this is a wrapper for libzmq 4.x. For 2.x, you need to check
ZMQ::LibZMQ2 and for 3.x, you need to check ZMQ::LibZMQ3