nysolfa was a web application for editing tonic solfa scores.
Around 2012 to 2014, it was accessible at http://nysolfa.org.
Since then, the webapp died.
However, nysolfa can still be used as a CLI tool.
nysolfa can produce solfège from solfa,
as well as corresponding midi sounds.
$ brew install lilypond
$ perl Solfa.pm ./sfexamples/fihirana-ffpm_441.sf 0 <-- use 0 for pdf generation
$ perl Solfa.pm ./sfexamples/fihirana-ffpm_441.sf 1 <-- use 0 for midi generation
Examples are given in ./sfexamples.
Technically speaking, nysolfa is a compiler from sf (a custom SolFa-based language) to lilypond. As lilypond is released under the GNU GPL license, hence so is nysolfa.