The Guido Quartz Viewer is a simple application to view and print Guido Music Notation (.gmn) files, using Quartz anti-aliased high quality graphics.
GUIDO Music Notation is a textbased, humanreadable format
to represent music. It is intended to describe musical
information as well as notational information. In GUIDO,
simple music can be described in a simple way, whereas
complex music sometimes requires more complex representations.
Freeware by Sourceforge