Sharing bit knowledge about Operating systems...

Microsoft Operating Systems
Microsoft is the most popular developer of computer operating systems. It has the greater share of the pie as their operating systems are greatly promoted throughout the world. This fact combined with their user-friendliness makes them the first choice of every new user.
Microsoft has many times criticized for adopting monopoly tactics and releasing incomplete operating systems that are vulnerable and unstable. This is the reason of the daily release of security patches, updates and service packs. Some of the most popular Microsoft operating systems are listed below:
• Ms-DOS
• Windows 95
• Windows 98
• Windows XP
• Windows 2000
• Windows Vista
• Windows 7
Linux Operating Systems
Linux is, in simplest terms, an operating system. It is the software on a computer that enables applications and the computer operator to access the devices on the computer to perform desired functions. The operating system (OS) relays instructions from an application to, for instance, the computer's processor. The processor performs the instructed task, then sends the results back to the application via the operating system.

Linux is an open source operating system that it was developed by Linus Torvalds and developers from all over the world. It begun as a hobby but now it is a very strong opponent to the commercial companies. Linux gains popularity every year and as a result hundreds of Linux editions have come out from many developers.
As an open operating system, Linux is developed collaboratively, meaning no one company is solely responsible for its development or ongoing support. Companies participating in the Linux economy share research and development costs with their partners and competitors. This spreading of development burden amongst individuals and companies has resulted in a large and efficient ecosystem and unheralded software innovation.
Although, Linux distributions are not so user-friendly as Windows or MAC, they are free. This is because Linux is an open source operating system. Another advantage of an open source OS is that every program that is designed for this computer OS is also free. Some popular Linux distributions for the mainstream users are the following:
• Debian GNU/Linux
• Gentoo Linux
• Mandriva
• SUSE Linux
• Fedora
• Ubuntu Linux



Apple or MAC Operating Systems
Mac OS X is a unique operating system in that it represents a rather successful coming together of paradigms, ideologies, and technologies that have usually resisted each other in the past. It is a result of the trials and tribulations of Apple and NeXT, as well as their user and developer communities. Mac OS X is perhaps one of the best examples of how a capable system can result through the direct or indirect efforts of corporations, academic and research communities, the Open Source and Free Software movements, and even individuals
Apple wanted to differentiate from Microsoft’s approach to computer OS and it was the first company that designed a fully graphical interface for their computer operating systems. When MS-DOS had just a command line waiting the user to start writing, the MAC operating system offered only a graphical environment without a command line support. Apple designed two families of MAC operating systems, the MAC OS and the MAC OS X.
Apple has been around since 1976, and many accounts of its history have been told. If the story of Apple as a company is fascinating, so is the "technical" story of Apple's operating systems
Apple’s operating systems are characterized from the easiness of use and the beautiful visuals. They offer a very nice and easy to use environment. Some versions of MAC OS X are listed below:
• 10 “Cheetah”
• 10.1 “Puma”
• 10.2 “Jaguar”
• 10.3 “Panther”
• 10.4 “Tiger”
• 10.5 “Leopard”
• 10.6 “Snow Leopard”