Whoa! Sinofsky, Windows chief and taskmaster, leaves Microsoft

This is a shocker. Steven Sinofsky, the prickly but super-efficient executive famous for delivering big products on time for a company not known for meeting production schedules, is leaving Microsoft (s msft). Now. His departure comes just a few weeks after the debut of Windows 8, the massive project he led.

The news was reported by AllThingsD‘s Ina Fried. Sinofsky’s role will be taken over by — get this — two women. Tami Reller who will take on the business side of Windows and Julie Larson-Green will direct Windows software and hardware engineering, according to a Microsoft statement. Larson-Green had worked with Sinofsky for some time.

For years Sinofsky headed development of Office, Microsoft’s juggernaut desktop productivity suite. His success there led to him taking over Windows after the Vista debacle.

Jeff Raikes, then the Office guy at Microsoft, has lauded Sinofsky to me repeatedly over the years. Sinofsky, he said, was the guy who delivered, who made the trains run on time.

Having said all that, Sinofsky was not particularly known for working well with others. Microsoft sources said he did not get along well with Ray Ozzie, who was hand picked by company co-founder Bill Gates to take over as the company’s chief software architect when Gates stepped back from that role. Despite those wrinkles, and because of his success in delivering product, some still considered Sinofsky a likely successor to Microsoft CEO Steve Ballmer.  In the past year or so, there has reportedly been tension between the two Steves. That may have led to today’s rather abrupt departure.

Last year, Robert Muglia, the respected president of Microsoft’s  Server and Tools group left after a difference of opinion over strategy with Ballmer, but in that case, Muglia stayed on for several months to ease the transition. There was no such arrangement in Sinofksy’s case.

In a statement, Sinofsky said:

“It is impossible to count the blessings I have received over my years at Microsoft. I am humbled by the professionalism and generosity of everyone I have had the good fortune to work with at this awesome company.”

Feature photo courtesy of Flickr user Microsoft Sweden