I tried http://www.oracle.com/technetwork/middleware/jrockit/downloads/index.html but all I get is
The content on this page is no longer available but your downloads may be found on the Oracle Java Archive page.
See Java 7 Questions & Answers (circa 2011):
Q: When will JRockit be available for Java 7?
A: It won't. As we explained last year we are merging JRockit and HotSpot into one single JVM. JDK 7 contains the first release of this converged JVM, where one of the first steps was to start removing the PermGen concept. Future JDK 7 updates will complete the PermGen removal, as well as add more visible features from JRockit.