@softgoat Found even better: modern applications that don't need emulators.
OpenMPT (many import formats, saves to IT, S3M and others)
DefleMask (multiple game console chiptunes, like NES and Genesis)
MuseScore (ok, not a tracker, it's for MIDI, but it's free score notation software)
FamiTracker (NES-only, but supports Famicom expansion chips)