On 15 Dec 2011 at 9:27, Toby Thain wrote:
  There's also LilyPond. 
http://lilypond.org/ 
I believe I mentioned that one when the thread was started.  The
problem with Lilypond is that it's like troff--straight text input.
Straight text is usable for applications such as troff, as you're
essentially going from text-to-text.  Try that with an orchestra
score where you have piccolo, 2 flutes, 2 oboes, cor anglais, 3
clarinets, 2 bassoons, 4 horns, 2 trumpets, 3 trombones, tuba,
percussion, harp, celesta, divisi first and second violins, violas,
'celli and double-basses--all with parallel scoring (e.g. take a look
at the full score for "The Nutcracker"). "Cumbersome"  doesn't
even
come close to describing the situation, particularly where there are
a lot of graphical elements involved.  There's a reason that musical
notation is complicated.
To be sure, there are front-ends such as Rosegarden, but most are
either in abandonment status or not ready for prime-time.  There's
been a slight move toward using MusicXML as an interchange medium, so
you could use your favorite WYSIWYG notation package, but MusicXML is
not exactly an "open" standard.
--Chuck