"The quality of the experience has to be unquestionably consistent with, as good as, and aligned with everything that people already know," Elop said.
In Microsoft's vision for how productivity applications evolve, users will edit and move documents between their personal computers, the Internet and mobile devices, without losing any of the formatting or structure of the documents.
"We talk about the best productivity experiences being those that are a combination of the PC, the phone, and the browser," he said.
Mobile versions of Office will be available for Windows Phone handsets, due later this year, as well as for Nokia smartphones running Symbian, and eventually MeeGo, Elop said, predicting that 200 million to 300 million Nokia handsets will be shipped with a mobile version of Office installed in the years ahead.
However, Microsoft has no immediate plans to offer mobile versions of Office for Research In Motion's BlackBerry handsets or Apple's iPhone. "We think hard about which scenarios need to be enabled on what devices, and at what point in time, because we have limited resources," Elop said.
"We'll consider other environments as we proceed, but there's no ambiguity that there's a requirement to consider each of these different platforms as our customers guide us," he said.
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