It is Apple Inc operating system for their Macintosh computers. It is referred to as OS Ten. (OS X) It started with 10.0.x, 10.1.x, 10.2.x, 10.3.x, 10.4.x, 10.5.x, 10.6.x.
Just like Windows 7 is Microsoft Corp operating system.
Macintosh OS X Tiger is an OS (Operating System) made by Apple. Mac OS X Tiger has nothing to do with tigers. The purpose of an OS is to run programmes on a computer.
Mac OS X 10.5 (Leopard)
Apple's Mac OS X is legally only used on Apple Macintosh computers.
Yes, if you have the Mac OS X version.
Mac OS X (ten)
You mean Macintosh OS x keylogger? It is keylogger softare for mac OS. The popular is Aobo mac keylogger or Safe Eyes
Mac OS X is the OS used on Apple's Macintosh computers.
widgets
Root
Apple's Mac OS X can legally only be used on Apple's Macintosh range of personal computers.
Mac OS X
IMHO - Macintosh OS X