LilyPond and MuseScore seem to be the big names now, but can anyone name more? Anyhow, according to one review I saw, LilyPond is weak on text editing while MuseScore has poor note selection. However, though, overall it could be said in the article that MuseScore was the best - but that didn't mean necessarily that LilyPond was terrible. Oh, by the way, regarding totally free stuff, I've used MusEdit, but this software is no longer updated and might cause problems with current computers. Nonetheless, it was powerful and so was/is Power Tab, a software used mostly by guitar players. but that program is still in operation I think.