We read in wikipedia:
"Mac OS X is the successor to the original Mac OS, which had been Apple's primary operating system since 1984 […] The first version released was Mac OS X Server 1.0 in 1999, and a desktop-oriented version, Mac OS X v10.0 followed in March 2001"
The funny thing about MacOSX launch was the huge hype on the retail box: it was named "The world's most advanced operating system" and really it was very huge leap ahead.
I won one of the original box of the v10.0, and the vectoriazed PDF interface was one of the most powerful even.
Windows has obtained a similar GUI only at the end of the 2007, more then five years later
For more information also see
- The first O'Reilly manual at http://www.oreillynet.com/pub/a/mac/2001/11/09/missingmanual.html
- Inital Announce