SoundGrail - SoundGrail Music App designed for pianists, guitarists, and DJs.
LMMS - Make music with a free, cross-platform tool
keezy - A colorful soundboard. Play with music.
Jokosher - Jokosher is a simple and powerful multi-track studio.
Figure - Propellerhead creates world-class software products and services that inspire music makers and provide the foundation for a worldwide creative musical community.
DSP-Quattro - DSP-Quattro