...

Introduction

IzPack installers use Java Logging for logging any information. If you want to customize it you should be familar with it, otherwise there is a good description of its principles in Oracle's Java Logging Overview.

...

Beyond the built-in logging mechanisms for console and file output there can be override the Java Logging configuration, handlers, formatters and their configuration at each desired Java package hierarchy you may add to an external configuration file, which can be passed as JVM command line option (standard approach of the LogManager API) or at compile time in the installer descriptor.

...