Mac OS X is the latest version of Mac OS operating system for Macintosh computers. The operating system was first issued in 2001 and is popular among users. The character “X” is the Roman number is ten, where this version is the successor of the previously used operating system like Mac OS 8 and Mac OS 9. Some people read it as the letter “X” that sounded like “ex”. One of the reasons why they interpret the tradition so as to give the name of the Unix-based operating system with the suffix “x” (eg AIX, IRIX, Linux, Minix, Ultrix, Xenix).
Released the first version (target servers), Mac OS X Server 1.0, 1999. The version released for the desktop, Mac OS X version 10.0, in March 2001. Since that, there are five other version has been released, is the latest Mac OS X v10.5 in October 2007. All versions of Mac OS X are named after big cats, for example, the Mac OS X v10.5 will be called “Leopard”.