Most JVM packaging tools cap out at four or five formats — jpackage, the JetBrains Compose default, install4j. Nucleus ships sixteen distributable formats from a single nucleus { … } block. Pick the ones you need; the build matrix takes care of the rest.

TL;DR

16 formats covering every mainstream desktop channel — App Store, Microsoft Store, Snapcraft, Flathub, GitHub Releases, ad-hoc URLs.
One Gradle DSL, one CI workflow. No CMake, no platform-specific maintainers.
Store builds get a separate sandboxed pipeline automatically (PKG, AppX, Flatpak).
Code signing, notarization, trusted CA bundling, and auto-update wire into the same DSL.

Install

The packaging DSL is part of the Gradle plugin — no separate dependency.

plugins {
    id("dev.nucleusframework") version "2.0.0"
}

Quickstart

nucleus {
    application {
        mainClass = "com.example.MainKt"

        nativeDistributions {
            targetFormats(
                TargetFormat.Dmg, TargetFormat.Pkg,
                TargetFormat.Nsis, TargetFormat.Msi, TargetFormat.AppX,
                TargetFormat.Deb, TargetFormat.Rpm, TargetFormat.AppImage,
                TargetFormat.Snap, TargetFormat.Flatpak,
                TargetFormat.Zip,
            )
            packageName = "MyApp"
            packageVersion = "1.0.0"
        }
    }
}

Then:

./gradlew packageDistributionForCurrentOS

Every format requested for the host OS lands under build/compose/binaries/.

Coverage matrix

OS	Direct distribution	Store	Universal archives
macOS	DMG	PKG (Mac App Store)	ZIP, TAR, 7Z
Windows	NSIS, MSI, Portable	MSIX / AppX (Microsoft Store)	ZIP, TAR, 7Z
Linux	DEB, RPM, AppImage	Snap, Flatpak	ZIP, TAR, 7Z

Sixteen total: Dmg, Pkg, Nsis, NsisWeb, Msi, AppX, Portable, Deb, Rpm, AppImage, Snap, Flatpak, Zip, Tar, SevenZip, and the intermediate RawAppImage. Pass them to targetFormats(...).

How it works

Under the hood Nucleus runs jpackage to produce a platform app-image, then hands that image to electron-builder's --prepackaged mode to drive every installer format. This hybrid keeps the JVM runtime jpackage tuning while picking up electron-builder's installer breadth — NSIS, MSIX, Snap, Flatpak, AppImage — none of which jpackage supports.

When you mix direct-distribution formats with store formats, Nucleus splits into two parallel pipelines: a regular createDistributable for DMG/NSIS/DEB and a createSandboxedDistributable for PKG/AppX/Flatpak that pre-extracts native libraries, injects sandbox-aware JVM args, and applies the right entitlements. See sandboxing.

Per-OS knobs live under nativeDistributions.macOS { … }, windows { … }, and linux { … } — see the dedicated pages.

Reference

macOS — DMG, PKG, universal binaries, Liquid Glass, layered icons → building for macOS
Windows — NSIS, MSI, MSIX/AppX, Portable → building for Windows
Linux — DEB, RPM, AppImage, Snap, Flatpak → building for Linux
Code signing · Trusted certificates · Sandboxing
Auto-update · Publishing · CI/CD
Full DSL: Gradle DSL reference.

Notes

The complete targetFormats list is the source of truth: dev.nucleusframework.desktop.application.dsl.TargetFormat. Formats not supported on the host OS are silently skipped at packageDistributionForCurrentOS time — useful for matrix CI where the same workflow runs on macOS, Windows, and Linux.

One DSL, sixteen installers