I think you've made a bit of a misconception here in confusing the underlying programming language (Java) with the UI library. Assuming you want a program to a

I think you've made a bit of a misconception here in confusing the underlying programming language (Java) with the UI library. Assuming you want a program to act and function naturally, like an OS X application - in which your problem is really down not to the programming language used. It is down to the libraries that are being used to develop the UI. Were people to be using Java as the language, but building from a Cocoa binding then you'd be able to have the same UX as a native app. Netbeans uses its own library, which is based on top of Swing. This doesn't feel native at all. It is also worth noting that there's a big difference between the Gui Libraries that Eclipse and Netbeans depend upon. SWT, the library that eclipse depends upon is actually using native widgets /most/ of the time underneath. Unfortunately it does a lot of its own UI stuff on top of those widgets, and doesn't really follow Mac OS guidelines. I still feel its an incredibly well designed UI though in many regards.