I'm surprised this targets TeX rather than lilypond, which AFAIK is the gold standard for free (as in beer and speech) music engraving.
I checked, and lilypond also offers features for Gregorian chant notation [1]. Has anyone used both and is able to compare?
[1] https://lilypond.org/doc/v2.25/Documentation/notation/typese...
Good question, they considered it at some point:
> Lilypond is a very good tool, but the part on Gregorian chant is not maintained and very deep modifications would be needed to perfectly align the notes and text.
Source: https://gregorio-project.github.io/gregoriotex/index.html