Ubuntu Studio is a free and open source operating system, and an official flavor of Ubuntu. Ubuntu Studio is the most widely used multimedia orientated GNU/Linux distribution in the world. It comes preinstalled with a selection of the most common free multimedia applications available, and is configured for best performance for the Ubuntu Studio defined workflows: Audio, Graphics, Video, Photography and Publishing.

ubuntustudio.org
Ubuntu Studio Applications
Ubuntu Studio Audio Handbook
ubuntustudiomusic.wordpress.com
wiki.ubuntu.com/UbuntuStudio
en.wikipedia.org/wiki/Ubuntu_Studio