The Linux drivers for Ubuntu can be downloaded from here
To install run:
sudo apt-add-repository ppa:mini-box.com/ppa
sudo apt-get update
sudo apt-get install nut-openups
Either reboot the computer or run:
sudo service udev restart
(plug openups into the usb port)
sudo service nut restart
For other versions of Linux driver must be compiled from source which can be downloaded from here.