Wenzel Jakob has released the Beryl XML GUI Library 1.0, an open source class library that enables developers to store Swing layouts as XML documents. It's published under the LGPL.
Version 0.9 of AspectWerkz, an open source aspect oriented programming framework for Java, has been released. According to the AspectWerk web page, "AspectWerkz utilizes runtime bytecode modification to weave your classes at runtime. It hooks in and weaves classes loaded by any class loader except the bootstrap class loader. It has a rich join point model. Aspects, advices and introductions are written in plain Java and your target classes can be regular POJOs. You have the possibility to add, remove and re-structure advices as well as swapping the implementation of your introductions at runtime. Your aspects can be defined using either an XML definition file or using Runtime Attributes." AspectWerkz is published under the LGPL.