#6 MAC OS X Server:

Within just years of release, the Mac OS has gained its coveted spot in the market of Linux operating systems. The first reason for its success is the brand name and value. The second reason, as important as the first, is that Apple has managed to create a very fast, reliable and dependent system that can run multiple applications, without any interruptions. Also users credit the operating system to be manageable and organized.  

One of the major disadvantages of the OS is that, or a sort of advantage, the operating system is pretty hard to reconfigure. That is once you configure server with the Apple Mac OS X, it’s pretty hard to reinstall the operating system or reconfigure it, as admins has to start the entire configuration from first, registers, hosts and scripts. So the Mac OS X Server is mainly intended for long scale projects as, they are for sure to be long enough.