Why can't I use the Windows and Mac look and feels on other platforms?
These look and feels are locked to only work on their native operating system. Sun felt there were copyright-related issues with running these on other than their native operating system.
If you really want to, you can enable this yourself. All you need to do is create a new look and feel that subclasses the specific look and feel. If you do do this, you will need to copy the icons from the original look and feel into the new look and feel. Otherwise, icons on dialogs will not appear.
In addition, if you only want the look and feel of a particular component, you can tell the UIManager to use the UI for the specific component.