Are there any high profile sites that run Mac OS X Server?
Certainly the most high profile site is Apple.com. They are one of the most visited sites on the net and they are powered by Mac OS X Server.

Certainly the most high profile site is Apple.com. They are one of the most visited sites on the net and they are powered by Mac OS X Server.
Mac OS X Server 1.0 was released in January, 1999. It was the first operating system that Apple released after their acquisition of NeXT. You can read more on Wikipedia.
As mentioned above the first version was released in January, 1999. Subsequently, the next versions of Mac OS X Server were based on the Mac OS X 10.0 code. The following releases followed: