Hackers over at XDA Developers have posted a Facebook application, apparently ripped from a Windows 6.5 ROM but installable on earlier versions of Windows (mobile).
The application isn't completely stable, though it will run on a wide variety of Window Mobile devices - we tried it on an Omnia with few problems. It's branded "Facebook" rather than the kind of derivative name normally applied to third-party clients (such as SkyBook and FriendMobilizer), indicating its identity as the definitive Facebook application for the Windows formerly known as mobile.
The explosive growth of social networks has left Windows Mobile lagging behind the competition, which should be a surprise given Microsoft's investment in Facebook; but Redmond has always seen Windows Mobile as being more of a business tool, while social networks are a bit silly. Integrated clients for version 6.5 are no great surprise, but Microsoft is going to have to work harder to achieve the kind of seamless integration that Palm have been demonstrating with the Pre, or that offered by alternatives such as Fring.
The new Facebook client does attempt minimal integration - a telephone icon produces a list of Facebook "friends" who are also listed in the on-device address book, allowing the user to call them from within the client, which is an indication of how things ought to be.
Of course, none of the social networks is making money just yet, and it's not easy to see how that's going to change any time soon. Facebook may be more popular than religion right now, but unless it can generate a profit the money being poured into developing custom clients could easily be going to waste. ®