MusiXTeX is a set of macros, based on the earlier MusicTeX, for
typesetting music with TeX. MusicTeX demonstrated that TeX alone cannot
practically typeset good-looking ties and slurs. There is therefore a
separate processor, musixflx, in the bundle, which uses the output of
MusiXTeX to position the slurs. As a result, MusixTeX is a three-pass
system: TeX, musixflx, and TeX again. This version of MusixTeX builds
upon work by Andreas Egler, whose own version is no longer being
developed. Raw MusiXTeX macros are universally acknowledged to be tricky
to write: most users employ the pmx preprocessor, which takes much of
the strain.