Microsoft's Cortana voice interface could be the game-changing interface Windows Phone needs. Source: Microsoft.

Will Microsoft's (NASDAQ:MSFT) new Cortana voice interface outperform Apple's (NASDAQ:AAPL) Siri? We'll need time to answer that question properly. Yet if initial reports are to be believed, Mr. Softy may already be outmaneuvering its rival. Fool contributor Tim Beyers explains what's happening in the following video.

On the surface, Cortana -- named for a computerized character in the popular Halo series of video games -- isn't much different from either Apple's Siri or Google Now. Rather, judging by comments made to The New York Times, Microsoft wants users to think of Cortana as a better assistant that anticipates what you need before you ask for it.

Tim says that's a transient differentiator, since software always improves and Apple, with its acquisition of Novauris in the U.K., is determined to upgrade Siri. Google, too, is likely working on improving Now. Where Cortana might genuinely set itself apart is in applications support.

According to the Times, Microsoft is working on an open interface for third-party developers to access Cortana's services. Future enhancements could include using voice commands to watch a TV program on Hulu or to compose and send tweets. Notably, Microsoft's Xbox already boasts similar features via its Kinect interface. Building on that legacy to improve the overall Windows Phone experience could boost not only the business but also Microsoft stock, Tim argues.

Now it's your turn to weigh in. Do you believe Cortana is a viable alternative to Apple's Siri? Please watch the video to get the full story and then leave a comment to let us know what you think, including whether you would buy, sell, or short Microsoft stock at current prices.

Tim Beyers is a member of the Motley Fool Rule Breakers stock-picking team and the Motley Fool Supernova Odyssey I mission. He owned shares of Apple and Google (A and C shares) at the time of publication. Check out Tim's Web home and portfolio holdings, or connect with him on Google+Tumblr, or Twitter, where he goes by @milehighfool. You can also get his insights delivered directly to your RSS reader.

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