Tutka

Tutka is a free tracker-style MIDI sequencer for GNU/Linux and Mac OS X. It is similar to programs like SoundTracker, ProTracker and FastTracker, except that it does not support samples and it is meant for MIDI use only.

Tutka uses a custom XML-based file format for storing songs. Songs in OctaMED SoundStudio's MMD2 file format can also be loaded and saved.