Compatible with Macs capable of running High Sierra, including Late 2009 MacBooks and iMacs, and Mid 2010 Mac minis, Pros, and MacBook Pros.
Does 5.6.3 delete deprecated services? - Apple Support Community
This version is the ultimate release for macOS High Sierra 10.13.6 . macOS Server 5.6.3
(Mail, DNS, DHCP, VPN, Websites, Wiki, Calendar, Contacts)
for new installs; fully functional for existing upgrades. Management Tools (Profile Manager, Open Directory, Xsan) Active and supported as the primary focus. Compatible with Macs capable of running High Sierra,
The defining characteristic of version 5.6.3 is how it handles traditional server services. This version began the process of services from new installations to signal their upcoming removal. Feature Type Status in 5.6.3
It served as a preparation point for the subsequent macOS Mojave-compatible version (5.7.1), which removed the vast majority of server features. The "Deprecated Services" Turning Point (Mail, DNS, DHCP, VPN, Websites, Wiki, Calendar, Contacts)
and integrated directly into the standard macOS System Preferences. Critical Post-Release Issues (2020–2025)