After many weeks of work, Zong! p0.4.51 is finally out. Although there are no new features which are interesting from a user’s perspective, there are two important changes which are essential for the future development of the project:

• The core has been completely replaced. While it was based on mutable Java classes and operations using many side effects before, the core is now completely functional. It is now much easier to test and maintain, and undo/redo is now a trivial task. The new core wouldn’t be possible without the excellent work of the pcollections project, which I can really recommend for Java projects of any kind.
• The musicxml project replaces proxymusic. While this is also a great library which I can recommend to all Java+MusicXML projects, we had problems with the Reflection techniques it is using (applets must be signed then), JAXB’s not-so-optimal XML-to-Java conversion and its speed (on my machine proxymusic needs about 2 minutes to load all official MusicXML 1.1 and MusicXML 2.0 samples, while our new musicxml library needs about 5 seconds). The two projects do basically the same, but proxymusic is automatically generated from the MusicXML schema, while our library is written by hand, which is really a very boring task, but finally it was worthwhile.

The goal for the next iterations is to rewrite the layout engine so that it fits to the functional core. Then, we can continue to improve the layout engine and support more music notation features. We also plan to offer a web service that converts MusicXML to PDF (and possibly other formats).