> by your definition, there never has been a multi-user operating system
Could be. Requirements have changed a lot in the last 10-15 years. Privacy was not such an issue before, when computing was mainly about engineering. How many new operating systems have appeared in the last 10-15 years?
Hmm, thinking twice... As a matter of fact I'm not sure whether the NT kernel supports it. At least it has more fine-grained priviledges than Linux. No idea whether http://msdn.microsoft.com/en-us/library/bb530716%28v=vs.8... is a complete list, I thought I had seen even more when using ProcessExplorer[1] some years back. And what about SELinux or grsecurity? Haven't looked at them in detail, but at least http://grsecurity.net/ lists:
> A restriction that allows a user to only view his/her processes