I just attended a Sun talk on their open-source work and tools. One useful tidbit was a demo of Netbeans. This is a java-based IDE for java, C, etc. If you’re on windows, solaris or linux they also have a killer set of J2ME tools for writing, debugging and running J2ME apps, complete with GUI phone and blackberry emulators.
Sigh. I’ll play with it on Mac anyway, I still wanna get a mud client working for blackberry. Or maybe IRC. Fun stuff.
UPDATE: The dev tools and emulators don’t exist for OSX or Solaris. Sigh. Exceedingly weak, that.