The swiss army knife of lossless video/audio editing
An open-source, clean-room reimplementation of Avid Pro Tools
LilyPond sheet music text editor
Layer-based headphone calibration, AutoEQ and FIR rendering
Runabc is a user interface supporting abc music notation software
Tool to lossless cut audio files
Audio Editor
Featureful native Commodore 64 music tracker with MIDI/XM converter
Miniak Hacks!
Fruityloops clone with sound samples using Fmodex lib
(Free)Play multiple videos / images simultaneously on multiple screens
Intuitive ID3 Tag utility for Mp3s
GS tag editor is a free tool for read and edit media file tags.
Print guitar chord diagrams
Music Manager focusing on ID3 tags and internal player