Mosquitto is a BSD licensed message broker that implements the MQ Telemetry Transport protocol versions 3.1 and 3.1.1.
Mosquitto is a lightweight broker and it is available in binary form for most used platforms like Windows, Linux and Mac OS X.
In a previous post I shown how to install mosquitto, on Raspberry Pi running raspbian, from source code.
On Mac OS X you could have some error because you should build all the environment for compiling.
Instead you could use brew.
from a terminal run the following commands:
Install mosquitto from brew:
$ brew install mosquitto
Prepare mosquitto for launchd
$ ln -sfv /usr/local/opt/mosquitto/*.plist ~/Library/LaunchAgents
$ launchctl load ~/Library/LaunchAgents/homebrew.mxcl.mosquitto.plist
Now let’s try the broker, in the terminal launch the subscriber client:
$ mosquitto_sub -h 127.0.0.1 -t topic
In another terminal launch the publisher client
$ mosquitto_pub -h 127.0.0.1 -t topic -m "Hello world!"
in the first terminal you should see the Hello world! message.