Software using the Apple Public Source License

XNU ("X is Not Unix") is the computer operating system (OS) kernel developed at Apple Inc. since December 1996 for use in the Mac OS X (now macOS) operating system and released as free and open-source software as part of the Darwin OS, which, in addition to being the basis for macOS, is also the basis for iOS, iPadOS, watchOS, visionOS, and tvOS.

XQuartz is an open-source version of the X.Org X server, a display server for the X Window System (sometimes shortened to X11 or X) that runs on macOS. In 2012, it formally replaced Apple's internal X11 app for OS X Mountain Lion (version 10.8). The name "XQuartz" derives from Quartz, part of the macOS Core Graphics framework, to which XQuartz connects these applications. XQuartz allows cross-platform applications using X11 for the GUI to run on macOS, many of which are not specifically designed for macOS. This includes numerous scientific and academic software projects.

password management system in macOS