Microsoft announced this morning that the next version of the Windows Phone operating system, code-named Mango, has been delivered to manufacturers who can begin testing it on their handsets.

The move is one of the final steps before the software arrives on new phones and is delivered to existing users as a software update.

"This marks the point in the development process where we hand code to our handset and mobile-operator partners to optimize Mango for their specific phone and network configurations," Terry Myerson, Microsoft's corporate vice president of engineering for Windows phone, wrote on a company blog. "Here on the Windows Phone team, we now turn to preparing for the update process."

The update, which brings multitasking and a complete overhaul of the built-in Internet Explorer Web browser, was first discussed in February, at Mobile World Congress. Two months later, Microsoft took the wraps off all the planned features, promising to deliver it in the fall.

Full story: c|net