The fork-join framework suggested by the JSR166y project does not belong in the JDK.
I've discussed this with the project lead, Doug Lea, several times to no avail. I’ve detailed the reasons for keeping the framework out of the JDK in this PDF file: http://coopsoft.com/dl/Challenge.pdf When you take a carefully, comprehensive look at what this framework does and how it does it, then you will see that it does not belong as part of the base of all Java programming.
