BARCELONA, SPAIN--Microsoft CEO Steve Ballmer offered a conciliatory hand to the wireless industry today, delivering an afternoon keynote address at 3GSM World Congress that promised a more open Microsoft willing to embrace interoperability and multi-vendor platforms as opposed to a Microsoft intent on dominating the market.

“We come as friends,” Ballmer said to a packed auditorium at the wireless industry’s largest annual conference. “We see an opportunity to change the world in a positive way.”

At a keynote designed to introduce several new innovations from Microsoft in the mobile realm, Ballmer took the opportunity to give Microsoft’s side of the story in the battle for phone software. Ballmer said that people perceive Microsoft as trying to dominate the wireless software and operating system space, but in truth it is only trying to develop an end-to-end services platform that can be taken as a whole or in part.

“The world is a heterogeneous world—it’s very important that we embrace that heterogeneity,” Balmer said. “If you want to build your own handset without our OS, we will license you our technology…. We’re trying to give you the tools for a great end-to-end experience, but we’ll embrace interoperability.”

The rest of Ballmer’s speech, however, was devoted to how Microsoft’s wireless efforts bridged back to its software in the wired PC world. Ballmer said that the newest versions of Microsoft’s Outlook and Exchange server would be built with wireless integration in mind, and he announced several new applications for the wireless market including a mobile version of its Communicator platform that extends IM and voice functionality into its Office desktop software.