/home/geertjan/Desktop/nbj/nbjfuguesupport/build.xml:7: The following error occurred while executing this line:
/home/geertjan/Desktop/nbj/nbjfuguesupport/nbproject/build-impl.xml:19: You must define 'nbplatform.NetBeans_IDE_5.5.1_(Build_200704122300).harness.dir'
To fix this:
In other words, the message above appears if you haven't set the platform for the JFugue Music NotePad. The platform (i.e., the NetBeans Platform) provides the underlying modules that the application is built on top of. Currently, the platform used by the application is NetBeans Platform 5.5 (or 5.5.1), which doesn't mean that you can't use NetBeans IDE 6.x for development purposes, of course.