Windows Server Core: Overview | SerkTools
Well, that's certainly a welcome change, of which I was not aware. I haven't used Windows as a server in years, since the only (or main) reason for doing so would be to support native functionality on Windows desktops. I'm almost tempted to try it … but not quite. The tiny box I cobbled together from spare parts in order to run a FreeBSD server probably wouldn't even boot Windows.
You do know with Linux the GUI is entirely separate from the underlying OS don't you?
Yes, but separate or not, GUIs consume a great deal of resources and introduce many complications to the system. While this may be justifiable on a desktop, it's a tremendous waste on a server.
Sometimes it's even a waste on the desktop. In one of my earlier computers I had a Windows FTP application that never seemed to reach the 10 Mbps speed of the LAN for transfers. I finally discovered that it was spending most of its CPU time painting its window, and when I switched to the simple CLI version of FTP that comes with Windows, transfer rates immediately rose to the capacity of the link.
To be honest its not a server if it has a keyboard and monitor attached.
That depends on your configuration and environment. While you certainly wouldn't put monitors and keyboards on every server in a server farm, if you only have one server (as I do), it's not a big deal to have a separate monitor for it. I do share the keyboard, though. It also has its own mouse, although I'm not sure where I put it (I never have a use for the mouse on the server).
Even so, I do SSH into the server from the desktop most of the time, as this is more flexible and makes it easier to have multiple "terminals" connected.
Which is why if you read my post I said running 'under z/VM' - in other words as a guest OS in a totally separate LPAR.
Guest OS or not, it's still not a mainframe OS. It's just Linux. Little server operating systems are lightyears away from mainframe operating systems.
Up until around the mid 70's when MVS 3.8 existed, it was public domain and able to be installed on any competitors hardware - Amdahl, ITEL.
Freely available and public domain are not the same thing. While earlier versions of MVS were published and readily available (I think—it's been a long time), I should be very, very surprised if IBM ever released anything into the public domain. I'm not sure if anything would have entered the public domain on its own. In any case, it's not as if one can install MVS on a PC or a PDP-11/70 (without emulation).