Compile once, dont run anywhere?

So whats this controversy or non-contreversy thing with Java all about? And what about compile once run anwyher? And isnt its SUNs Job to get things work on the OS plattform they support and not Apple?

Ok. To make me understand: at the beginning of this year i joined the OpenJDK discussion lists and i was told the Vista is not one of SUns favorite OSes for Java 7. Now everyone seems to acknowledge that Windows Vista is - despite the problems with Vista Microsoft has - the very one plattform and MAC is not. So whats up with Java 7? Is it going to run on MAC, Linux, Vista or only Vista and Linux?.