Darwin (operating system)
Darwin is the core Unix operating system of macOS, iOS, watchOS, tvOS, iPadOS, visionOS, and bridgeOS. It previously existed as an independent open-source operating system, first released by Apple Inc. in 2000. It is composed of code derived from NeXTSTEP, FreeBSD, other BSD operating systems, Mach, and other free software projects' code, as well as code developed by Apple.
Window Maker in XDarwin
Unix is a family of multitasking, multi-user computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, and others.
Ken Thompson and Dennis Ritchie, principal developers of Research Unix
Photo from USENIX 1984, including Dennis Ritchie (center)
Promotional license plate by Digital Equipment Corporation, actual license plate is used by Jon Hall
HP 9000 workstation running HP-UX, a certified Unix operating system