Free Libre Music Notation Software Search

I'm looking to start using Free Libre Open Source Software (FLOSS) for my occasional music notation and midi creation. I bought Myriad's Melody Assistant ages ago and have used it pretty happily, but I now have a piece I would like to print with a little higher quality notation, so I'd like to upgrade to Myriad's Harmony Assistant or go some other way. I have Linux up and running, but at the moment, Windows is still more convenient for me.

Here's my summary that's perhaps more up to date and contributes in some way beyond Dave Phillips's Feb 2008 summary.

I'm looking into:

• Lilypond (Linux/Win). The standard music engraver. But I don't want to write text files directly. I want a GUI with audio playback. All the GUI packages export for Lilypad.
  
• Denemo (Linux/Win). Front end GUI for Lilypond, but not very popular.
  
• Noteedit (Linux only). Dead project, but still very popular.
  
• Rosegarden (Linux only ). Widely used.
  
• Canorus (Linux/Win). A successor to Noteedit. People have high hopes, but slow development.
  
• Musescore (Linux/Win/Mac). Very new. Lot of excitement. Mac version not incorporated into main branch yet.
  
• Nted (Linux only). A successor from the founder of Noteedit.

I downloaded Lilypond and Musescore to a WinXP machine so far, and I hope to post again when I have some further results.

See Part 2