[devbent]

Windows has had multi-user support for ages.

That is how user switching in XP works, and how RDP works. You can have an arbitrary number of sessions of logged in users at once, only limited by the license for what version of Windows you have installed.

There have also been versions of Windows that allow multiple users to interact with each other at once, but I believe these have all been cancelled and I do not know to what extent these simultaneous users had their own accounts.

[kev009]

Well of course, Windows XP is a direct decedent of Windows NT. Maybe you are referring to Citrix or Terminal Server, which are also Windows NT technologies.