Have you used Google Apps and seen where multiple people can work on a document simultaneously? Office 2010 will have that same functionality and it will leverage SharePoint as the common document store.

The goal for multi-user editing is to allow you to act independently of others while editing the same document at the same time using a rich text editor. To be effective, multi-user editing must handle file level conflicts, within document conflicts, merging of changes, and managing multiple copies of the same document.

Currently, OneNote 2007 supports Shared notebooks which provide a level of multi-user editing. Office 2010 enhances and extends that functionality across all the Office products. Below, I have detailed each of the ways multi-user editing is allowed in each product. The big take-away for me is that you get similar features to Excel Services in SharePoint 2007 if you have Office 2010 and SharePoint Foundation Server.

OneNote 2010

• Changes made to content on a page by multiple users are updated in real time.
• Notebooks can be stored in SharePoint just as in 2007.
• Page versioning has been implemented.
• The name of the user making the change is displayed next to the change.
• The OneNote 2010 Web App is used to edit OneNote notebooks w/o needing the OneNote application.

Word 2010

• Status bubble tells you that someone else is also working on the document.
• People icon lets you see who is working on the document along with their presence information.
• Paragraphs are locked as they are being edited.
• Navigation outline displays icons on the section being edited by someone else.
• Someone w/o Word would view the document through the Word Web App. Document can be edited via the Web app also.
• SharePoint versioning is supported and those versions can be viewed from within Word.

PowerPoint 2010

• Same type of notifications as in Word.
• Locks are applied at the object level – clip art, text, shapes, etc. Two people can be working on the same page at the same time.
• Users are notified of conflicting changes.
• Broadcast Slideshow – Broadcast slideshow via SharePoint. This creates a URL that can be sent to users who want to view the presentation. This loads through the PowerPoint 2010 web app. REALLY COOL NOTE: SharePoint 2010 (Server and Foundation) now assigns a unique document ID. This means that a document URL will ALWAYS be the same no matter where it is moved to in SharePoint.

Excel 2010

• Uses roles – Author and Contributors. Contributors can use Excel Web App to view and contribute.
• Author posts spreadsheet to SharePoint using the Excel Web App.
• Status bar in lower right indicates how many people are editing the spreadsheet.
• Locks are applies at the sheet level (need to follow-up on this to be sure this is correct).

Technology Used

The files are cached locally and synced via a file provider to SharePoint. The MS-FSSHTTP file provider sends only the changes to the users as part of each sync. MS no longer uses WebDAV for this type of communication.

A related technology is inside Windows Server 2008 R2. If a user opens a document across the WAN and his/her neighbor (I assume same VLAN) opens the same document later, the server will get the document from the original user and save the trip across the WAN.