Which is the Java 6 to download: JDK or JRE?

When I tried the JDK, my Limewire, which is already consuming 99% of my CPU, stated: "Limewire is unable to read Java", and would not open.

So I have gone back to Java 5 and am using the pretty good FSR program http://www.filesharingrevolution.com/ for downloading music and video.

I hope Limewire come up with a proper fix soon. In my experience, Limewire support has not been too good.