TeXmuse is a program (under development) for musical typesetting. Its main feature is that it automates many areas of musical typesetting that have not been addressed by available software, and that make music typesetting an unduly time-consuming and error-prune task.
TeXmuse is also built on the assumption that non-standard notation (any deviation from those automatic defaults) should be as easy, intuitive, and accessible as standard notation.
Signature automation capabilities
Line breaking. No need to fix the breaking of the music into systems in each part, or every time you change something. The program finds a satisfactory distribution.
Spelling and courtesy accidentals. No need to check transpositions for c-flats, e-sharps, etc. The program also decides (but is flexible) on courtesy accidentals, with no need to check when it would be affected by a change in meter or copy-pasting between staves.
Beaming. TeXmuse will correctly beam a 3/4 bar as one beam of six eighth-notes, or break it into beats when sixteenths are present. (This as an example of the capabilities that are built into the program.)
Voice splitting. Double-instrument staves (say, the flutes in an orchestra) can be output as one staff or as two independent ones, toggling a single command.