Sinofsky left Microsoft on December 31, 2012. His departure was described by both parties as a mutual decision, but widely seen externally as the result of a power struggle or friction between himself – tipped as a future leader of the company – and CEO Steve Ballmer. Technology website Ars Technica drew attention to the sense of staffing changes after a major project – the Windows 8 rollout, but also noted the abrupt and exceptional manner of departure and a similar analysis of recent politics within Microsoft by ZDNet. Sinofsky was succeeded by Julie Larson-Green and Tami Reller. Larson-Green will run the engineering function of Windows, while Reller will oversee the business operations. Microsoft disclosed in an SEC filing that Sinofsky would have a one-year non-compete contract in exchange for an estimated $14M of stock.