Microsoft's Windows operating system family is an egregious example of closed source operating systems and the risk to consumers from overly-controlling manufacturers. Many of us worry what Microsoft does with information collected from its customers, and chafe at the lack of control we have over our computers. But the popularity of Windows means there's lots of enticing software and a large number of folks comfortable in that environment. As they might wish for an open alternative, with a strong NO SPYWARE guarantee, they want a thing which behaves like Windows. Getting there means undertaking an effort to reverse engineer a Windows implementation in the open source world.