IzPack Utilities

IzPack utilities

The IzPack project includes a set of utilities that you may find useful.

These projects live outside the regular IzPack installer Subversion repository. You can access it from http://svn.berlios.de/svnroot/repos/izpack/izpack-utils/ instead of http://svn.berlios.de/svnroot/repos/izpack/izpack-src/ for IzPack itself.

They will be shipped in the official IzPack releases under their own pack.

Windows executable wrapper (izpack2exe)


The 7-Zip project (see http://www.7-zip.org/) provides a so-called SFX for installers, i.e., an image that can be use to create self-extracting Windows executables. Once its content has been extracted, such a self-extracting executable can launch an executable or a file. In the later case, it is assumed that there exists an association between a file extension and a software component.

7-Zip SFX for installers works as follows:

  1. an executable image is provided
  2. a configuration file has to be written, specifying among other things the executable or the file to be launched after the extraction phase
  3. a 7-Zip archive containing the files (including the executable of file to be launched)
  4. these files simply need to be concatenated to form a SFX Windows executable.

The IzPack Windows executable wrapper takes an IzPack-generated installer JAR file, and wraps it inside a Windows SFX executable. This has several advantages, among these two ones:

  1. some users may find it strange to have a JAR and not an executable
  2. by naming it with setup or install, Windows VISTA will perform a rights elevation whereas IzPack cannot enforce it when launched as a regular JAR.

And of course, you can ship a JAR and a Windows executable from the very same IzPack installer descriptor!

We have customized the SFX image from the 7-Zip project as follows:

  • we have changed the icon
  • we have customized some strings to mention that this is a customized version.

While the rest of the work is licensed under the Apache License version 2, the sole SFX module is licensed under the Lesser GNU General Public License version 2 or later as required by the 7-Zip project.


izpack2exe is written in Python. It depends on 7-Zip and optionnaly UPX, a tool that can compresses executables.

In official IzPack releases, we provide this tool batteries-included on Windows, i.e., we will provide:

*izpack2exe as a Windows executable, so that you don't need to install Python, and

  • 7-Zip and UPX executables, so you don't have to download them.


The usage is quite easy:

usage: izpack2exe.py [options]

  -h, --help       show this help message and exit
  --file=FILE      The installer JAR file / files (1 per bundled file, specify at least the installer JAR!)
  --output=OUTPUT  The executable file
  --with-7z=P7Z    Path to the 7-Zip executable
  --with-upx=UPX   Path to the UPX executable
  --no-upx         Do not use UPX to further compress the output
  --launch-file    File to launch after extract (e.g., native launcher)
  --with-jdk       Bundle a JRE/JDK with the .exe, eliminating the needing for a JRE just to run the installer. Points to the root of the desired JRE

A typical wrapping will be done like:

izpack2exe --file=installer.jar

Mac OS X Application bundle wrapper (izpack2app)


izpack2app is the Mac OS X brother of izpack2exe. It bundles a JAR installer inside an application bundle, so that your installer will look like a regular Mac OS X application.

To do that, we started from the Mac OS X Jar Bundler tool that you can find under /Developer/Java. We bundled a Jar installer, then stripped it. Indeed, an application bundle is nothing else but a structured set of files and directories.

What izpack2app does is simply:

  1. copy the bundle files structure,
  2. put your Jar at the good place, and
  3. edit the Info.plist to reference your Jar.


izpack2app is written in Python. It does not require any third-party module to work. Python is bundled with Mac OS X and is mainstream on Linux and other Unix variants. We ship it as a Windows executable in the official IzPack releases (and of course also as a Python application!).


The usage is straightforward:

izpack2app.py installer.jar Installer.app

wraps installer.jar as Installer.app

Java Web Start JNLP file generator (izpack2jnlp)


izpack2jnlp is able to generate Java Web Start JNLP files so that IzPack-based installers can also be shipped via Java Web Start.


izpack2jnlp is written in Python and does not need third-party modules to work.

Please note that it only generates JNLP files: you must sign your installer JAR before you actually upload them to a web server as Java Web Start refuses to launch unsigned JARs.


You need to pass a few arguments on the command-line, run:

izpack2jnlp.py --help

to see them.