Microsoft Monday revealed its plan to acquire Nokia's mobile business in a deal valued at $7.2 billion. The acquisition, Microsoft hopes, will ramp up the company's relevance in the mobile device market and give it an edge over competitors Apple and Samsung. Nokia is one of a slew of acquisitions Microsoft has finalized since 2011. The acquisition lineup points to Microsoft's commitment to cloud computing, social media, advancing its Xbox gaming console and Xbox Live capabilities, as well as its move toward hardware, especially in the mobile device market. Following are 12 deals the software giant has closed since May 2011.