\input zb-basic \input zb-ioport \iteman{io-port 05301587} \itemau{Bortolazzi, Enrico; Baptiste-Jessel, Nadine; Bertoni, Giovanni} \itemti{BMML: A mark-up language for Braille music.} \itemso{Miesenberger, Klaus (ed.) et al., Computers helping people with special needs. 11th international conference, ICCHP 2008, Linz, Austria, July 9--11, 2008. Proceedings. Berlin: Springer (ISBN 978-3-540-70539-0/pbk). Lecture Notes in Computer Science 5105, 310-317 (2008).} \itemab Summary: The need of an interchange format for music notation led to several XML encoding initiatives and among them to MusicXML, a de facto standard format supported by market leaders. The result is that music scores can be shared between applications and between users, delivered through the web and/or archived independently by the application that generated them. Braille music is a specific music notation for blind users, written in linear format, character by character. Traditionally Braille scores in electronic format are archived or shared as text files, with only character information dependent on some translation table. The available XML formats for music notation are not suitable to cover this specific notation. We present our approach to the problem and the key design concepts behind Braille Music Mark-up Language, developed as an open format by the EU funded CONTRAPUNCTUS[1] project. \itemrv{~} \itemcc{} \itemut{Braille music; music notation; XML; BMML} \itemli{doi:10.1007/978-3-540-70540-6\_46} \end