Some pointers to things useful for Free Java.

• gcj, of course
• GNU Crypto provides javax.crypto support
• Jessie provides JSSE support, aka javax.net, javax.net.ssl, and javax.security.cert
• Tom Fitzsimmons' JHBuild for gcj and friends.
• Jipsi (site in German) provides a CUPS back end for javax.print
• Jacorb or OpenORB for CORBA support.
• Java-Gnome is nice java bindings for Gnome APIs
• gcjwebplugin, for running applets in Mozilla and elsewhere
• rhug has a little bit of everything, all nicely pre-packaged for use with gcj
• Java LDAP bindings. There's also some from Mozilla, and an abandoned Java LDAP server on sourceforge.
• OpenJNLP. This is one piece of the webstart puzzle -- a way to run java applications directly off the web. Anthony has an implementation of javax.jnlp to go along with this. It turns out there are a couple more of these: Java URL (no URL handy) and netx. netx might be the best one at the moment; it has a comparison page. The OpenJNLP page has pointers to some webstart programs, which would be useful for testing.

Some Mozilla stuff I haven't really investigated:

• BlackConnect, an XPCOM/Java bridge.
• JRex, a way to embed Mozilla in a Java program.

Some cool projects I'd like to see:

• Fix up gjdoc not to be so slow. Make it work with Ashkelon.
• Enhance java-gnome to let you write panel applets in Java. Ideally, go one step farther and let them run in a secure context, and let the user drag-and-drop jar files from Mozilla onto the panel
• Write a GConf back end for java.util.prefs. Better yet, use UniConf.
• Update Classpath to use the URL providers in inetlib by default
• A Swing plaf that can read Gtk theme files.
• A nice Java wrapper for gstreamer. The existing bindings don't appear to be complete yet.
• An implementation of javax.sound.sampled.spi that works with gstreamer
• A Java wrapper for DBus (AIUI java-gnome has this now)
• A plugin for eclipse that teaches it how to use libgcj as a target VM. Ideally we would be able to develop some parts of libgcj directly in eclipse.
• We could make it simpler for folks to write native methods which just map some C library API. We would do this by having a "linker" class that would know how to use libffi to make stubs which wrap the functions in question. Then this could all be done dynamically. For libgcj we could have a special flag and implement a different sort of call, so that we wouldn't even need the stub in some cases and could just put a pointer to the C function into the vtable. Take a look at GDirect if you're interested in this.
• Would it make sense to write a javax.naming back end for GConf? For Java LDAP it would certainly make sense.
• A JDWP implementation for libgcj. One way this could work is by wrapping gdb and using it to do the difficult parts of the work. The org.eclipse.cdt.debug.mi.core plugin from Eclipse would be useful here -- it is relatively independent of the rest of Eclipse, and can be used to drive gdb programmatically via MI.
• Have Classpath javadoc link directly to JExamples.com.