Symbian shifts mobile world to open source

OS that competes with a fully featured one that is offered for free," he said. Windows Mobile will have to become free, or close to free, to remain competitive as the mobile market increasingly favors open source, he said.

Microsoft thinks differently. "I've been asked, Are we changing our strategy?" said Scott Rockfeld, group product manager for Windows Mobile. "Absolutely not."

By moving to open source, Symbian "opens themselves to the same challenges that other open-source OSes have encountered, which is fragmentation," he said.

One concern about Android, for example, is that manufacturers are expected to be able to deploy components of the operating system as they please. That could create difficulties for application developers, since applications may not be run evenly across all Android devices.

With proprietary software like Windows Mobile, a developer can create an application and know that it works across all Windows Mobile phones, Rockfeld said.

He also doesn't expect the cost of licensing Windows Mobile to become an issue. "The reality is that the cost of the OS pales in comparison to bringing the phone to market," he said.

As for RIM and Apple, some observers said they probably won't be affected by Symbian's move. RIM has a solid foothold in a very specific market -- that of e-mail-centric mobile devices, said the LiMo Foundation's Shikiar. Gold said Apple's loyal customer base is likely to continue supporting its products, although in time, as more features are added to Symbian, the iPhone may feel pressure.

Overall, the shift that Symbian is causing toward most smartphones being open source is a significant one for the mobile market. "Ultimately the drive toward openness is a profound and undeniable force underway," Shikiar said.

(Stephen Lawson in San Francisco contributed to this report.)