NoteAbility is a comprehensive music notation editor that now exists in a variety of implementation on a variety of platforms. The program was designed to provide a user with a simple and direct user interface and to provide a high degree of graphical flexibility. The basic design of NoteAbility will be presented, and some its unique interface properties will be discussed. The remainer of the talk will focus on the import and export facilities of NoteAbility and, in particular, on the GUIDO support offered by NoteAbility. Support of GUIDO not only provides NoteAbility with the option of exchanging data with other programs, it also enhances the functionality of NoteAbility by allowing the inclusion of GUIDO modules that perform new operations.