Developers warned that Microsoft's new phone OS does not allow users to switch back and forth between live third-party apps.
Apple's iPhone 4 may have a serious antenna flaw, but it's still got a leg up on Microsoft's forthcoming Windows Phone 7 operating system in at least one crucial area—the ability to run more than one third-party application at once.
A Microsoft employee confirmed Tuesday that Windows Phone 7 won't be capable of true multitasking, the absence of which could limit the appeal of devices based on the OS among road warriors and other demanding users.
"Windows Phone allows only one application to run at any given time in the foreground, and no 3rd party applications are allowed to run in the background," wrote Microsoft technical evangelist Yochay Kiriaty, in a note to developers Tuesday.
"Therefore when a user navigates away from your application, either to a chooser like picture chooser, or to a launcher like phone call, Windows Phone operating system terminates your application," Kiriaty said.
"Tombstoning is the procedure in which the operating system terminates an application’s process when the user navigates away from the application. The operating system maintains state information about the application. If the user navigates back to the application, the operating system restarts the application process and passes the state data back to the application," Kiriaty added.
Windows Phone 7 will, however, allow some Microsoft firmware apps to run in the background in an always-on state, Kiriaty said.
Apple is touting the fact that iPhone 4, and older iPhones upgraded to iOS 4, allow users to run more than one app at once and switch back and forth at will. "Now you can run your favorite third-party apps — and switch between them instantly — without slowing down the performance of the foreground app or draining the battery unnecessarily," Apple boasts on its Web site.
In Microsoft's favor is the fact that Windows Phone 7 devices are likely to include an antenna that actually works.