Updated from 1:24 p.m to include number of Office users, and cost of Office for iPad.
At an event in San Francisco, where Nadella discussed the intersection of cloud and mobile, the new CEO announced Office would be coming to Apple's popular tablet, making it the first time Office has been on a tablet other than the Microsoft Surface.
"Everything that we do gowing forward, is grounded in this world view -- the world of ubiquitous computing," Nadella said during the press conference. "The world in the next five, 10 years will not be defined in the form factors that we know and love today, but new ones. It will make computing ubiquitous."
"We describe this, and you see it today, with the growth of the number of users connected to the Internet with their devices. That's what's going to be everywhere. All of these things have applications. Connected growth of these devices and these applications are leading to the rise of cloud computing," the CEO added.
As of 2 p.m. EDT, Office for iPad will be live on Apple's App Store. It has all the features users are familiar with in Office, said Microsoft's Julia White, the general manager of Microsoft Office, during the announcement. White noted Office, which has over 1 billion users, will have "freemium" business model on the iPad, allowing users to read and present Office content. With an Office365 subscription, which costs $9.99 per month or $99.99 per year (students can pay $80 a year), users can create as well. This is just the beginning of Office moving to other platforms, White said.