Even before macOS 10 (then Mac OS X 10) was available to everyone, there was a server version intended for running fleets of Mac computers in businesses, schools, and other organizations. Apple has slowly phased out macOS Server over the past few years, by moving most of its functionality to other places in the Mac operating system, and now it’s officially discontinued.
Apple confirmed in a support document that macOS Server is discontinued as of April 21, 2022. macOS Server in its current form is just an application running on top of a normal macOS installation, and the app is still available to download and is fully compatible with the latest macOS Monterey release.
macOS Server (Credit: Apple)
Some services in the app are available in other areas of the system, like File Sharing, the Caching Server, and the Time Machine Server. However, several other features in recent versions of macOS Server require switching to a slightly-different solution or third-party software — the servers for email, Wiki management, FTP (not SFTP), and VPN don’t have direct replacements in regular macOS. The Profile Manager in macOS Server is perhaps the most important component, and Apple’s only recommendation is switching to a third-party option like Microsoft Active Directory.
macOS Server first arrived as Mac OS X Server 1.0 in 1999, released a whole year before the first public version of Mac OS X. Apple later replaced it with a customized version of Mac OS X 10.0 once that version became available in 2001, which had various server applications and services built-in. Starting with Mac OS X 10.7 Lion, Server became an App Store app running on top of regular macOS. Apple also added features over the years for managing iOS devices, in addition to Macs and cross-platform services.