pfSense

Once upon a time ZMQ was intended to be a potential logging or notification type, but that hasn't been touched in quite some time.

We still include libraries and modules for it, and a couple lines of code, all of which can be removed since they are not needed.

etc/inc/syslog.inc:        if (isset($syslogcfg['zmqserver'])) {
etc/inc/syslog.inc:*.*                                ^{$syslogcfg['zmqserver']}
etc/rc.php_ini_setup:PHPMODULES="$PHPMODULES zmq" 

The following libraries and dependencies can be removed after the other references to zmq are removed:

libzmq4-4.3.4
php74-pecl-zmq-1.1.3_3