Appcast

Appcasts are consumed by auto-updater frameworks (most commonly Sparkle on macOS) to compare the installed version string against the latest available version and download the delta. The feed lists version numbers, release notes, file URLs, and checksums. Because version strings in the appcast are parsed by the auto-updater’s own parser, any deviation from the expected format (such as hyphenated suffixes) silently breaks the update check on affected builds without surfacing an error to the user.