Competition, Industry Structures, and Regulations Microsoft Microsoft Corporation is the largest software company in the world. It develops office productivity software, software for servers, operating systems for mobile handhelds, the Windows operating systems for computers, and the Xbox 360 video game system. Because tablet computers use competitors' operating systems and sometimes cloud- based office software, sales of Windows operating systems and Microsoft's Office productivity software have declined. Microsoft earns the bulk of its revenue from its Windows operating system and its Office productivity suite. To broaden its product lines, Microsoft has developed a cloud computing platform whereby its software customers are able to use office and collaboration applications hosted in Microsoft's data centers. Collaboration software enables groups of people to work together simultaneously on documents and projects that are stored in centralized databases. In another step to becoming more web centric, Microsoft introduced its Bing search engine in 2009. Bing is now the third-largest search network in the United States, behind Google and Yahoo! Prior to developing its own search software, Micro- soft attempted to acquire Yahoo!; however, Yahoo! rejected the merger offer. But, it did form a ten-year partnership wherein Microsoft provides Yahoo!'s core search technol- ogy in exchange for 20 percent of Yahoo!'s search revenue. One of Microsoft's most successful recent innovations is its Xbox 360 video game system. Xbox 360 includes game consoles, accessories, and the actual game software. In 2010, Microsoft introduced motion-sensing capability for the Xbox 360, the Kinect for Xbox. Microsoft was the first video game publisher to develop a way to control video games through hand and body gestures. Kinect for Xbox 360 reacts to ges- tures including kicking, punching, ducking, diving, and jumping. In another effort to become web centric, Microsoft purchased 17.6 percent of book store Barnes & Noble's Nook e-book subsidi