Lloyd's Java Shell is a java scripting tool (it could read and execute java-like statement from any input stream) that could easily be plugged into an application and modify its object - so it is also a configuration tool. It is also a good test tool, as you could easily use it to test any feature of your new object.
Mincom Base is the lowest level of the Java code written for Mincom's MineSt*r project. It includes pluggable logging (better than JSR047), resources, pluggable serialisation, and chained exceptions. There are other useful bits, like assertions, a simple and reliable shared buffer, stack trace capture and analysis, and a Map implementation with weak references to values.
Nirvana is a Java based message oriented middleware package supporting the publish subscribe model. It supports message persistence and XML DOM Documents as well as straight TCP communications and HTTP/HTTPS tunneling. Nirvana supports a federated namespace and instances can be joined together. Matrix is a connector framework providing "out of the box" connectors for most commonly used middleware products. Matrix supports a "many 2 many" configuration in a single instance and allows the user to define transactions that define relationships between source and destination systems.
The XML to Java via Reflection (XJR) project was created to provide an easy way to connect xml with java objects. It uses Reflection as a means for connecting and creating the java objects it creates, and it can use any type of java object such as RMI objects or EJB beans. It also provides a DTD compiler that will generate Java source code "bean-style" for a given DTD.
CDKeeper is a cd collection organizer. It helps the user keep track of data-cd collections (backups, file archives, etc.) by allowing them to import CD file-structures, comment every file, directory, or CD (if desired), and then search the collection for a file. This helps the user locate files they might not otherwise be able to locate quickly in a large collection.
Universe is an Open-Source game which resembles Master Of Orion. It is written in Java. The goal is to have as few arbitrary limits as possible, allowing games as large as you wish. It also supports a concept called "Schemes" which allows programmers to develop distinct rule sets and extensions.
NetStereo is a server which runs on a computer with a sound card and plays music, primarily MP3s. What makes the NetStereo server special is that it accepts commands from remote clients. The server is written in Java, and it features the ability to plug in various methods of playing songs (currently mpg123 and the Java Media Framework) and various methods of communication (currently network and serial port). Currently available clients include a Java client which uses the Swing toolkit and a Palm client.