Getting the operating system
The DiscoHAT has only been tested on an optimized image created by Massimo Callegari.
You need to make a donation to the QLC+ project in order to download the image. Instructions are on the page http://www.qlcplus.org/raspberry.html
The sources are free so you can also compile your own version and install it on some other OS distro. But the DiscoHAT does not provide a pre-compiled binary for other OS distros.