mosquitto-update-raspberrypi

# fixed: http://jpmens.net/2013/09/01/installing-mosquitto-on-a-raspberry-pi/
# ref: https://mosquitto.org/2013/01/mosquitto-debian-repository/
# to get newer versions 1.4.+

wget http://repo.mosquitto.org/debian/mosquitto-repo.gpg.key
sudo apt-key add mosquitto-repo.gpg.key

cd /etc/apt/sources.list.d/
sudo wget http://repo.mosquitto.org/debian/mosquitto-jessie.list

sudo apt-get install mosquitto mosquitto-clients python-mosquitto

# mosquitto is the MQTT broker (i.e. server)
# mosquitto-clients are the command-line clients, which I recommend you install
# python-mosquitto are the Python bindings, which I also think you should install
# all three packages together require about 665Kb of space, which we can easily afford even on the tiny Pi.