Can You Identify All The Operating Systems In The Restart Page?S

I love The Restart Page: it faithfully reproduces the restart and shutdown sequences of most graphic user interface-based operating systems since the times of the original Macintosh System. See if you can identify them all without hitting the restart button.

Post in the comments how many you got right. I got 15.

It's really perfect, sound included. Except that it makes me feel really old because I ran almost every one of these the day they came out. [The Restart Page via Twitter]