On the Facebook developers conference f8, Mark Zuckerburg announced that Facebook will be launching a collaborative document-editing tool with Microsoft. Over 1500 software developers and FB app developers were present in the conference. You can watch f8 live on Facebook.
Docs.com is a join collaboration of Facebook and microsoft. Built on Microsoft Office 2010, the Docs app enables Facebook users for the first time to create and share Microsoft Office documents directly with their Facebook friends, using the Office tools they already know.
Documents can be created directly within the app, or can be uploaded from your PC. You can share the document with your selected friends or all the friends or with the whole world. Documents can be viewed and edited directly within a web browser – or, with a single click, you can edit them more richly and powerfully through the Microsoft Office software on your PC or Mac.
Docs is currently in limited beta. You can sign up to be notified when it’s available for you to use by connecting your Facebook account.
Docs – Homepage