Sparkle is an easy-to-use software update framework for macOS applications. It delivers updates using appcasting, a term used to refer to the practice of using RSS to distribute update information and release notes.
Sparkle was originally created by Andy Matuschak in 2006, and eventually went on to become the de-facto standard for macOS application updates, used by thousands of applications including Evernote, Oracle Java, Mailbox.app, SourceTree, TeamViewer, VLC Media Player, X11.app, and many, many more.
At the end of 2013, Andy stopped development of Sparkle and handed over maintainership to the newly formed Sparkle Project, a group of developers dedicated to managing and maintaining the official Sparkle open source project going forward. The Sparkle Project currently develops and maintains Sparkle on GitHub with the help of dozens of valued contributors.