Mixxx is Free DJ software that gives you everything you need
Virtual MIDI controller for Linux, Windows and OSX
abcmidi is a library of programs to handle abc music notation files
Specialized sound synthesizer with Byzantine Church music scales
Extends LilyPond functionality in order to write microtonal music.
music composition and notation software, audio to midi converter
Music score editor
App for capturing/sending data from joystick, MIDI, OSC
Midi Modifier Module
Convert your text typing into music
Scrolling notes in any key for any instrument