Where is IBM Java 1.5 for Windows?

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.

Comments (12)

  1. Kris says:

    I remember in the early 2000 IBM used to give away a lot of development tools for free for developers or with a limited license. I am surprised that now you can’t even download their JDK. How can you woo the developers on their platform? They should learn from Microsoft and Oracle.

  2. Tom Kerigan says:

    IBM has a no-compete clause with Sun, with respect to the JRE, on certain platforms, including Windows. This means that IBM is not allowed to ship a standalone version of the JRE for these operating systems unless it is at least one major version prior to the current version (in this case, JRE 1.4.x). As you pointed out, there still are ways to get IBM’s 1.5 JRE for Windows (ie. by installing a bundled product like Rational Application Developer or one of the web services toolkit), but it’s not standalone, that’s for sure.

  3. lp says:

    Download Websphere 6.1 trial, J9 is in there. Indeed with some very cool extensions like class sharing between JVMs.

  4. Stan says:

    It looks like the IBM 1.5 JDK for Windows is contained in their Development Package for Eclipse.  Still a 100 MB download, but the whole package is free …


  5. whitetiger says:

    Get it here:


    You can get around the bios check by either

    unpacking the installer or letting the installer

    unpack itself and then copy the java setup file(s) from your temp folder

    not sure about v5, worked with 3 & 4

  6. cheeso says:

    Just to be clear, I absolutely do not advocate subverting the license enforcement or violating the license agreement on IBM’s software, or anyone’s software.  


  7. Samir Gouda says:

    I downloaded the Development Package for Eclipse, but I can’t use the JRE.

    If I run java -version, I get "No Public JRE", even though I have replaced my old java.exe (from sun) in c:/windows/system32, and I have uninstalled SUN JRE.

    How do I tell my system to use the IBM JRE?

  8. vipera says:

    The installer does not extract the setup files prior to running the BIOS check, but it does extract a program called ‘checkIBM.exe’. Run that program at a command prompt and you should be able to figure out how to trick the installer.

  9. cheeso says:

    I absolutely don’t recommend tricking the installer or subverting the license.  I am saying that there exists a 1.5 Java VM from IBM, and people should check the license to verify that they have rights to use it in the way they want to.


  10. Denis says:

    I had to install the IBM JRE on my PC, because our production environment is running under WAS 6.1 with the IBM JRE, while my local PC is running under Tomcat 5.5 / SUN JRE.

    I had a compatibility issue between the 2 JREs (about Xerces and stuff), so the only way to test was to get an IBM JRE on my PC which unfortunatly is a non IBM PC.

    After getting dumped twice by the installer of the JRE because my PC is a non IBM one, I managed to get around the check fairly easily just by looking a the temp folder and its content.

    Non competition is fine, but in my case I had to get the JRE to be able to test on my local PC the IBM JRE…

  11. amit patel says:

    you also get IBM SDK 5 as part of WASCE download