1 Opéra Libre is written by Valentin Villenave (http://valentin.villenave.info/).
2 Most of the text was written by Lewis Trondheim (http://lewistrondheim.com/).
4 None of this would have been possible without LilyPond, the GNU music typesetter,
5 written by Han-Wen Nienhuys and Jan Nieuwenhuizen (http://www.lilypond.org/)