When talking about operating systems, we generally talk about 3: Windows, Linux and Mac. But there are others! gHacks has already covered ReactOS; a free and open source version of Windows, but there are many other operating systems out there which not many people use. BeOS was a commercial operating system which died during the [...]
ReactOS: Open source Windows
Windows is a proprietary operating system which you cannot compile or modify at a sourcecode level. This allows Microsoft to maintain control of their operating system and many people disagree with the notion of using closed source software. ReactOS is a free and open-source operating system, which has been in the alpha stage of development [...]