Windows - To get the JDK for windows is a tricky one. You have to download IBM Development Package for Eclipse. This will give you a eclipse Europa (3.3) version, along with J9 JDK version 1.6.
Previously J9 was the recommended VM for running the harmony class files, as their own version of JVM was incomplete. Have a look at this wiki page.
In the end of November, 2006, the
language support provided by these
virtual machine was still incomplete,
and the build instructions recommended
to use IBM's proprietary J9 instead to
run the class library test suite.
However, this is not necessary anymore
(as of July 2007). The DRLVM virtual
machine is currently (as of July 2006)
under heavy development, so a fast
improvement of its features can be
expected
As McDowell suggested in his comment. You can get the J9 JDK from this link: https://developer.ibm.com/javasdk/downloads/. Specifically..
Linux - https://www.ibm.com/developerworks/java/jdk/linux/download.html
Windows - To get the JDK for windows is a tricky one. You have to download IBM Development Package for Eclipse. This will give you a eclipse Europa (3.3) version, along with J9 JDK version 1.6.
Previously J9 was the recommended VM for running the harmony class files, as their own version of JVM was incomplete. Have a look at this wiki page.
http://en.wikipedia.org/wiki/Apache_Harmony