appimagetool vs IzPack

appimagetool is a free Linux command-line utility that creates an AppImage from an existing AppDir. It is intended for application authors packaging desktop Linux software for distribution across common Linux distributions. The project describes it as a low-level component and recommends community higher-level tools for most users. Command-line options cover listing AppImage files, setting or guessing update information, selecting Squashfs compression, and excluding files. GPG signing is supported with a signing key and additional arguments. When update information is embedded and zsyncmake is installed, the tool can create a zsync file. Build instructions list x86_64, i686, aarch64, and armhf targets. The current version downloads the latest AppImage runtime, or accepts a local runtime file. Update information can be guessed from GitHub Actions and GitLab CI environment variables. An AppDir is required, and ARCH must be set when binary architecture cannot be determined, such as with multiple architectures or shell scripts. Source code is under the MIT License, subject to stated exceptions and dependency terms.

IzPack generates installers for packaging, distributing and deploying Java applications. It creates one installer that runs on operating systems with a Java virtual machine, with Windows, Linux, Solaris and Mac OS X listed as destinations. Users can select installer components and appearance, then extend installers with additional features. Optional native integration can create desktop shortcuts, modify a system registry or switch to an administrator account. Documented capabilities include command-line packaging, silent installation, auto-update support and CI/CD integration. Output includes standard JAR installers, web installers and pack JARs. The download page identifies IzPack 5.2.7 as the current release. A Maven plugin is documented, with links to independent Gradle, Scala SBT and Apache Buildr plugins. IzPack is published under the Apache Software License 2.0. The project uses mailing lists for updates and feedback and accepts GitHub pull requests. The Windows native launcher from IzPack 4 is not supported in version 5 because it lacks a maintainer.