NEW YORK -- Microsoft Corp. has said its new software for smart phones, Windows Phone 7 series, is a "clean break" with the past. Now it's clear just how clean that break is: The new phones, expected late this year, won't run any applications written for older versions of Microsoft's phone software.
In a blog post Thursday, Microsoft executive Charlie Kindel, who handles contact with outside software developers, said that jettisoning support for older applications was necessary to make the new operating system as powerful and user-friendly as possible.
The announcement is perhaps most disappointing to companies that have created their own software to run on Windows phones issued to their employees. The news also leaves software developers with a dilemma: they can write applications for Windows Mobile 6.5, which will soon be a dead end, or they can write for Windows Phone 7, which isn't coming out until later this year.
Phone providers compete in part by providing support for as many applications as they can, and everyone is trying to catch up to Apple Inc.'s successful App Store, which has more than 100,000 applications. Microsoft is leaving behind tens of thousands of applications written for different versions of Windows Mobile that go back more than a decade.
Few of those applications are up to today's standards. They're also designed for phones that came with styluses for precise input. Windows Phone 7 Series is designed for touch screens that work well with fingers but don't work with fine styluses.
Palm Inc. made a similar "clean break" last year, abandoning an operating system that was more than a decade old in favor of a completely new one. However, the new system is able to run applications written for the old one.
Kindel said Microsoft still will support Windows Mobile 6.5 "for years to come," and expects some new devices with that software will come out.