Write to the developer of ABC Navigator and you get no acknowledgement whatever. As far as I'm concerned, that attitude means a piece of software is dead.
Have to agree with that. I'm still surprised about the key signature problem as I thought it used abcm2ps (unless abcm2ps has the same problem)

I don't have a problem calculating semitones for transposition, but I find myself fingering an imaginary piano keyboard as I count the semitones. Specifying the source and output keys (or even just the output key as long as the ABC source is clear about key) shouldn't be hard as the program already knows enough about keys to work it out. I wonder what key abc2abc generates if e.g. you transpose G down a semitone (F# or G flat: 6 sharps vs. 6 flats)

ABC2WIN: this program is a disaster.
Absolutely. It has ruined the standardization of ABC by being broken and widely used at the same time. You could be forgiven for thinking it was a Microsoft product...

Anahata