Microsoft announced today that its upcoming smartphone platform has reached the RTM milestone -- the final development stage before shipping to Europeans in October, and Americans in November. The company said internal engineering is "largely complete," but hardware and carrier partners still have work to do. Only a handful of changes were made to the RTM build: Facebook contacts filtering and "Like" capability added to the People hub, and various UI tweaks, including a new search button in the contacts list.

Windows Phone 7 is said to be Redmond's "most thoroughly tested mobile platform." It had nearly 10,000 devices running automated tests daily, over 500,000 hours of active self-hosting use, more than 3.5 million hours of stress tests, and 8.5 million hours of fully automated tests. WP7 was also used by thousands of independent vendors and early adopters. "We are ready," said Microsoft. We're not sure how that compares to others, but it sounds impressive nonetheless.