mxml2abc is a commandline tool which converts single and multiple voice MusicXML files into ABC files.
This release improves robustness and adds more features including grace notes, C clefs, repeats, and staccato and crescendo marks. MusicXML v.3 is now supported. Some crashes and bugs have been eliminated.
URL: mxml2abc - Convert MusicXML to ABC Music Notation Language - Google Project Hosting