Sparkle is a software update framework for macOS applications. It provides a system for delivering automatic updates using signed archives and RSS-based feeds to notify clients of new software versions.
The framework ensures software integrity and authenticity through public-key cryptography, requiring digital signatures for both update archives and release feeds. It includes mechanisms for signing key rotation to maintain the security chain if a private key is lost.
To optimize delivery, the project includes tools for generating binary delta updates that ship only the byte-level differences between versions. The system handles updates through background installation processes and provides options for customizing the visual branding of the update interface.
