At Build 2015, Microsoft is greatly expanding on how it hopes to make its Office productivity suite a genuine platform, and it all revolves around apps. Apps that run inside Office. "We want to move far beyond individual apps and their APIs," said CEO Satya Nadella. He outlined some "fundamental changes" revolving around the user experience. Mainly, Microsoft is giving developers the ability to create add-ons that work across Windows, the web, and Microsoft's Office apps for iOS.

Demonstrations shown at Build included Uber running inside Outlook for iOS; you can automatically schedule a ride based around existing calendar appointments. "You're no longer going to different applications for different data," he said. Microsoft will give developers access to these tools over the coming months.

Developing. Check out our Microsoft Build 2015 Live Blog for the latest updates