Under the strategic alliance Nokia will adopt Windows Phone as its principal smartphone platform. Nokia also will assist with the future development of Windows Phone, contributing expertise on hardware design and language support. And Nokia and Microsoft will engage in a number of joint marketing initiatives.
Nokia also will use Microsoft's Bing search technology across its devices and services, while Nokia Maps will become part of Microsoft's mapping services. And Nokia's content and application store will be integrated with the online Microsoft Marketplace.
"Ecosystems thrive when fueled by speed, innovation and scale," Ballmer said at the press conference. "The partnership announced today provides incredible scale, vast expertise in hardware and software innovation, and a proven ability to execute."
With Windows Phone becoming Nokia's primary mobile phone operating system, Symbian will become "a franchise platform, leveraging previous investments to harvest additional value," the company said in a statement. There are an estimated 200 million Symbian devices in use and Nokia said it expects to sell another 150 million over time.
Nokia also said that MeeGo, the Linux-based mobile operating system the company has been developing with Intel, would become "an open-source, mobile operating system project" with potential for "longer-term market exploration of next-generation devices, platforms and user experiences." Nokia said it still plans to ship a MeeGo-related product later this year.