Where is IBM Java 1.5 for Windows?

Where can I get IBM's Java 1.5? This is the oft-asked but rarely answered question on IBM's developer forums.

Being a guy focused on interop, I like to test Windows and .NET interconnect with various other systems, many of them are Java based. Hence my interest in the IBM JRE and JDK.

IBM is supposedly a Java booster, undoubtedly a JCP EC member, and clearly uses lots of Java in their products, but the company does not offer a standalone JRE or JDK for Windows. Yet they offer the JRE and JDK for Linux. Why?? It's a puzzle to me, but I am guessing there is some sort of license agreement between IBM and Sun (owner of Java) that says IBM will not distribute Java for Windows separately.

Too bad. The IBM JDK 1.5 is really hot. I went to a session at JavaOne given by IBM on the advances they've made in their J9 JVM, and it looked really cool. In my own tests, the performance gains over IBM JRE/JDK 1.4.2 were quite substantial. (there were also significant perf differences between the IBM JRE and the Sun JRE, but I'm not going to comment on them!!)

Tests?!?! But without a download, how would that be possible? The IBM JRE and JDK for Windows are available only via some higher-level product, like the DB2 v9 beta, or Websphere App Server v6.1.

An Idea?

I suppose what you could do is, download one of those products, install it, extract the JDK/JRE bits and zip them up, then uninstall the higher-level product. The resulting zip should contain all the required files for the JRE and JDK. Unzipping it should give you a usable JDK. I don't know if that would violate the EULA for the IBM product, but technically it should be possible to do. Someone should check on the license issues.

Recommendations for Java on Windows

Probably the easiest answer, for those who want to use Java on Windows, is to use Sun's Java. There are other options, notably BEA's jRockit. If you really want to use IBM's J9 JVM, then it seems there might be a way to do it, if you were motivated enough, and assuming the licensing does not get in the way.