What OS would /g/ recommend for a midrange system that needed to handle an application that serves 2500-5000 concurrent users, and requires at least 3 processor books?
GNU
>>54749029
quite honestly it depends on how much the application needs to be updated.
if it requires maintenance or updates of any type your best bet will always be the latest matured edition of Windows Server
otherwise if its more along the lines of "deploy and forget" you can choose linux of just about any flavor.
>>54749029
16.04 server
>>54749029
netbsd or openindiana
Gentoo
>>54749277
probably AIX
Windows 10
>>54749487
kek
Debian.
Windows Vista or Gentoo