Microsoft's Windows Phone 7 has finally released to manufacturing (RTM). While the final integration of Windows Phone 7 with Microsoft's partners? hardware, software, and networks is underway, the work Windows Phone team internal engineering team is largely complete.

Windows Phone 7 is the most thoroughly tested mobile platform Microsoft has ever released. Microoft said that it had nearly ten thousand devices running automated tests daily, over a half million hours of active self-hosting use, over three and a half million hours of stress test passes, and eight and a half million hours of fully automated test passes. Thousands of independent software vendors and early adopters have been also testing Microsoft's software.

Since the Technical Preview milestone some months ago, the Windows phone team has improved the smart design throughout the OS. For example, the Facebook integration in the People Hub allows users to filter the contacts so only the Facebook friends they really know will show up in their contact list.

The team also made it easy to "like" a post right from the People Hub, or quickly post a message to someone?s Facebook wall directly.

The first Windows 7 phones will reach consumers later this year.