There are certainly numerous reasons for hating Java during development, especially when you know way more powerful programming languages like Objective-C, but one thing that really drives you mad soon is the lack of any user-definable warnings in your code! Using this little tool you'll instantly get C-style warnings working in your code! Instead of using #warning foo you'll have to use // @warning foo but that doesn't make a big difference.
This little program is written in Objective-C and finds its way into ProjectBuilder by posing as a new Java compiler. In fact, it's just a shell script that you'll have to put in place. The shellscript itself acts as a wrapper for calling the javapp program and the real javac. In doing so you can use your favourite Java compiler and don't have to touch its source ... nifty.
There's a README included in the source release which explains briefly what you'll have to do in order to use the tool. If you're curious now and wish to download the source for Mac OS X Server via ftp or http, feel free to do so! ;-)