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# History of Operating System

Most OSs are generally divided into two families: Unix-based and Microsoft NT descendants.

**Unix** was an OS developed in the mid 1960s. It's the "grandparent" of many modern operating system that we frequently use now, such as Linux.

The Unix operating system was a closed source project (meaning its code and files weren't made public). And this led to the rise of the "Free software" movement led by Richard Stallman. It argued that users should have the freedom to run, copy, distribute, and collaborate on the source code of a project.

**Microsoft NT descendants** were proprietary graphical operating systems that Microsoft created. The Windows NT descendants don't natively have similar Linux commands, unlike Unix and Unix-based Operating Systems, which do. Instead, Microsoft NT has its own set of commands and default shells.

Microsoft NT's offspring includes Windows, Xbox OS, Windows Phone/Mobile, and others.


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