[Tails]

Excuse me, but your list should be like this:
Modern Operating Systems:
Windows 9x (95, 9
Windows NT
Windows XP (5.1)
Microsoft Longhorn (Unreleased) (NOT the beta of Vista, but Longhorn before the restart, before it was going to become Shitsta)
Windows Vista (6.0)
Windows 7 (6.1, yes, it's not version 7. )
-
Mac OS X 10.6 (Snow Leopard)
Mac OS X 10.5 (Leopard)
Mac OS X 10.4
Linux Ubuntu (And derivates.)
Linux Slackware (And derivates.)
Red Hat Linux (And derivates.)

Classic operating systems:
Windows 1
Windows 2
Windows 3.0
Windows 3.1
Windows 3.11
Windows 3.2
Windows NT 3.1
-
System 1, System 2, and all the way to Mac OS 9, since I'm lazy to list them
<insert old distros of Linux that I don't know here>