Mixxx is Free DJ software that gives you everything you need
Midiexplorer is designed to explore a large collection of midi files
Ballroom Music Player
audio sequencer
A music tracker software for Windows.
Simple visual and acoustic metronome with bar-based song part tracking
Your Hardcore Loop Machine for Windows, Linux and OS X.
Loop based software with jack transport, record and midi controllable
Tapita is a BPM detector.
VST instrument playing mp3 files
Control Jack transport features using MIDI commands.
Calculate the BPM of a song!
MIDI and/or Custom WAV Metronome for Windows and Windows Mobile
Simple free metronome for training musicians
Simple musical track editor + Tools