Gnome-GCJ is a set of GTK+ and GNOME bindings for Java. It compiles with the GCJ compiler (part of egcs) and uses the GCJ runtime library libgcj. GCJ is capable of compiling Java source code to native machine code, which makes Java code almost as fast as C++ code. As the interface between Java and GTK+, CNI (Cygnus Native Interface) and C++ will be used instead of the more traditional JNI and C. This means that support for other Java runtimes has been sacrificed in favour of GCJ and its faster CNI.
GNUstep is a cross-platform, object oriented environment composed of frameworks, tools, and servers (daemons). It is very similar to the Cocoa frameworks from Apple, and tries to maintain compatibility with Cocoa wherever it is desired and possible. The frameworks provide classes for containers, distributed objects, object archiving, file management, text system, font management, image composition, WYSIWYG PostScript graphics, and more.
JIGS (Java Interface for GnuStep) allows Java programmers to use the GNUstep libraries from Java, but it is more than a set of bindings for GNUstep from Java: it takes advantage of the fact that Objective-C and Java are very similar languages to make it possible to use Objective-C classes from Java using exactly the same API (and vice versa). Moreover, JIGS can generate automatically wrappers for your own Objective-C GNUstep libraries.
JStart gives the ability to start Java class files (or applets) by double clicking on them from the desktop like any executable program. You only have to assign *.class files to this program. It loads a class file, investigates it according to the Java Sun class file specification, extracts the full class name (including packages), and invokes the main method of that class.
ResCafé is a Swing-based Java utility for reading and extracting resources such as ICONs and MENUs from the Resource Forks of Macintosh files. In particular, it allows Linux users to use nifty Mac-only icons with their favorite desktop, e.g., KDE. It is somewhat similar to ResEdit on MacOS except that it is not an editor; it operates on files in a read-only fashion. The various resource types are parsed by auto-detected plugin handler classes.
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.