A new Open Source Software Development Center is open at University of Belgrade Serbia. It centers around using Java & NetBeans as open source projects to learn from and contribute to. Assistant Professor Zoran Sevarac says that not only does the center allow him to teach software development using open source projects, but also "we are improving our University courses based on the experience we get from working on open source code."
Some of the projects underway are a NetBeans UML plugin; Neuroph (a Java neural network framework, with a NetBeans Platform-based UI); a NetBeans DOAP Plugin; WorkieTalkie (NetBeans chat plugin); and 2D and 3D visualization plugins for NetBeans. Here's video describing the NetBeans UML plugin: