Marcos Guglielmetti has announced the fifth test release of Musix, a 100% free multimedia operating system intended for music production, graphic design, audio and video edition, and all kind of tasks.
From the Musix Wiki:
It is a Free Operating system intended for musicians and users in general. It also contains an enormous collection of free programs. The system will boot from your CD/DVD drive, with no need to install anything on your hard disk. The programs currently support the Spanish and English languages.