Have a look at above page, see this: (as posted time 2006-09-06)
Java 2 Platform, Standard Edition (J2SE)
IBM Developer Kits and Runtime Environments are available for the following platforms:
AIX -- Downloads,Overview, and News
Linux® -- Downloads, Overview, and Tested platforms and distributions
z/OS web site
IBM 32-bit Runtime Environment for Windows
This is the IBM 32-bit Runtime Environment for Java 2 (JRE), Windows Edition. To be able to install this JRE your computer must be an IBM system, as shown by a BIOS check. It must also be running Microsoft Windows Me, 2000, or XP. Or it must be updated with the latest WMI classes if running an older Microsoft operating system. And, finally, you must have Administrator level access.