Windows Server
Microsoft partner. Remember NT?
Unix/Linux
Starting in 1988 we've had experience and training in managing SCO Xenix, Altos Xenix, SCO Unix, AT&T Unix, IBM AIX, Suse Linux. Microfocus partner.
Mac OS
Limited experience. Connecting to Windows network and supporting marketing and design applications.
Novell Netware
Again since 1988, Netware 286 and up to last version 6.5.