Further information:

HARMONY
1. Allows MIDI import and export
2. Uses multiple voices (including in abc format)
3. Uses and plays back grace notes
4. Prints the score
5. You can Drag and drop chord symbols onto score from a toolbox
6. Displays Guitar tab and other stringed instruments (definable)
7. Optionally play back repeats
8. Score can be enlarged for the visually impaired

Yes, there are some bug and quirks, but the same goes for all software!