Here's my plug for ABC over MIDI - ABC is able to better preserve notational subtleties such as beamed notes better than MIDI. Whenever I load a MIDI file into my MIDI software (Music Magic), the notes that were previously beamed are shown as separate notes. This doesn't make any difference to how the computer plays it, but it could make a big difference to a musician trying to sight read the music.

On the down side, I think that ABC will only handle one staff of music - unless someone has extended it's capabilities.

Some software titles (most are available for downloading as shareware on the internet):

For printing sheet music from ABC: Muse and ABC2Win (see message from me on 19 Nov, in this thread, for a link)

For printing sheet music from MIDI: Noteworthy Composer (www.ntworthy.com, I think) and SongWright.

There was a short thread a few days ago discussing Muse and Noteworthy composer. Click Here.

Incidentally, I have heard of a new file standard called NIFF - Notation Interchange File Format - which I believe will be as powerful as MIDI and also capable of retaining all features of printed sheet music. Look for future releases of music notation software to support this standard.