Task switching in Ubuntu, and a introduction to ‘The Spread’

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A key part of any operating system user interface is how it enables the user to switch between multiple tasks. In most desktop operating systems tasks are encapsulated into windows, and the most frequently used method of multi-tasking is window switching. Desktop OSs have multiple methods of window switching (e.g Alt-tab, clicking on indicators, notifications, etc…) 

credits:http://design.canonical.com/2012/03/task-switching-in-ubuntu-and-a-introduction-to-the-spread/