Microsoft Windows Server
Including Active Directory, Azure, and Small Business Server. Have managed innumerable print queues and file shares.
Including M365/O365 Azure and physical servers located in data centers as well as network closets
Nobody should host their own email server anymore.
IIS, Apache, NGINX
I have run my own website since 1995 and have managed a team of web developers.
Microsoft SQL / MySQL
I do not consider myself a DBA but I have managed multiple SQL servers as well as a couple of MySQL servers.
MacOS / AUX
OS X never succeeded as a server operating system.
It has been many years since I’ve seen a Sun server or Sun workstation.