Sparkle is a software update framework for macOS that handles secure and reliable application updates with minimal developer effort.
The framework solves the problem of distributing updates to macOS applications by providing a complete update system that requires no code changes to the host application and only static files on a web server. It uses RSS-based appcasts for release information and verifies updates through EdDSA signatures and Apple Code Signing. The approach supports delta updates that patch only changed files, atomic-safe installations, and automatic permission handling with authentication prompts when needed.
Developers maintaining native macOS applications should choose this tool if they need a straightforward update mechanism without building custom infrastructure. It suits applications, package installers, preference panes, and plug-ins, and in version 2 it extends to updating external bundles and sandboxed applications. The framework offers customizable user interfaces and supports beta channels, phased rollouts, and critical update marking. It requires an HTTPS server for serving updates and macOS 12.0 or later at runtime.
The project maintains active continuous integration with automated testing on recent commits. Development follows a documented roadmap tracked through milestones, and the team publishes detailed internal design documentation alongside the codebase. The project distributes nightly builds from successful workflow runs in addition to formal releases, allowing developers to test unreleased changes.
