One of the most anticipated features in SharePoint 2010 is co-authoring. This is the ability for multiple users to simultaneously edit a document without the burden of having to check out a copy. This can speed up workflow cycle times because users no longer have to wait for someone else to check in their copy before they make changes. Instead, users can collaborate together on a document and finish the work product in a fraction of the time. This functionality has been available in Google Apps, and is a welcome addition to Microsoft Office. In this blog post, I will explain how it works, and how it compares to co-authoring in Google Apps.
To get started, the document library setting ‘Require Check Out’ must be set to ‘No.’ That’s it! That is the default for a new document library, so you only need to change this setting if it was modified from the default. http://technet.microsoft.com/en-us/library/ff718246.aspx
The default setting on a new document library is ‘no versioning’. If you enable versioning, then you should consider increasing the number of versions.
By default, SharePoint will save versions every minute or so based on the coAuthoringVersionPeriod property (a setting modified by using powershell on the SharePoint server). This setting specifies how often SharePoint stores a version of a document that is being edited, measured in minutes. If the value is set to 0, SharePoint Server will capture every change made by a new user in a different version of the document. http://technet.microsoft.com/en-us/library/ff718243.aspx
Co-Authoring does not appear to work well when versioning is not enabled. In my testing, I got mixed results. Sometimes the changes would merge on their own, other times I was prompted to merge changes.
Co-Authoring in Action
Each Office product implements co-authoring in a different way. For example, Word 2010 uses Paragraph-level locking to prevent users from changing the same text simultaneously. Excel locks just the cell. If a conflict occurs in Excel, the one who made the last change wins. If a conflict occurs in Word, the losing user is presented with the winner’s word choice along with the selection to accept or reject their change.
Another difference between how Word and Excel Web App operate is Excel does not have granular notification capabilities—it cannot, for example, notify one user that a colleague is currently entering data into a particular cell, row, or table. So when a conflict happens, "last update wins", the change that is completed last will persist. This is not obvious when it occurs, and so teams should communicate with each other during the editing process to eliminate these errors. This scenario does not happen in Google Docs because you can actually see what the other user is typing as they type it. Microsoft will need to incorporate this same real-time visibility to make co-authoring competitive with Google Docs.
I will walk through this process below.
Step 1 - On a SharePoint 2010 Server, browse to a Word document and open it. If Office Web App has been installed on the SharePoint server, then the document will open in the web browser.
Note: Business customers licensed for Microsoft Office 2010 through a Volume Licensing program can run Office Web Apps on-premises on a server running Microsoft SharePoint Foundation 2010 or Microsoft SharePoint Server 2010. Co-authoring is not available in Word Web App, so you must click ‘Open in Word' if you want to simultaneously edit with other users. In Excel, just the opposite is true; co-authoring is only possible in Excel Web App and not the full version. Click here for more information on Office Web App.
Step 2 – Click Open in Word
Step 3 – Select Edit. If you are prompted to check out a copy, you must change the document library setting ‘Require check out’ to ‘no’ as described above.
Step 4 – Repeat steps 1 through 3 with a 2nd user so that two users are making changes to the same document.
Step 5 – You will only be able to see the other person’s changes when the user manually saves the file.
During co-authoring, users will be able to see the names or initials of the other people working on the document from a menu in the desktop applications' File menu or by hovering their mouse over a status bar at the bottom of the screen.
If you click on the ‘2’ icon then you can see who is editing the document.
In Excel, it looks like this:
You can also interact with the other editors by clicking on the File > Info menu.
After you click save, you are informed that the document has been refreshed to include changes from other users.
As soon as a user starts making changes to a paragraph, that paragraph locks and the name of the editor appears to all other users who are also editing the document. They will be unable to make changes to that paragraph until the first editor saves the document.
If versioning is not enabled, then users will be prompted to resolve conflicts when they click the save button.
Then, users can accept or reject any conflicts.
Comparison with Google Docs
There are a few notable differences between Microsoft Office and Google Docs:
| | Excel Co-Authoring | Word Co-Authoring | PowerPoint Co-Authoring | OneNote 2010 Co-Authoring |
| Microsoft Office 2010 w/SharePoint | Available w/Web App only | Full 2010 Client Only | Full 2010 Client Only | Web App or Full Client |
| Google Docs | Available in Web | Available in Web | Available in Web | N/A |
While Google Google Docs supports web-based co-authoring, Microsoft currently only offers this with Excel Web App. According to this blog, co-authoring is coming to the other Microsoft Web Apps in the 2H 2010.
One noticeable difference between Office 2010 and Google Docs is Google users can see exactly what is being typed by others users as it is typed, whereas in Word 2010, changes are only visible after the save button is pressed. It is much closer in Excel, where users can see changes immediately after leaving a cell, but you cannot see who is making the changes. In Google, the name of the user making the changes is shown above the cell.

Communication between Google Doc users editing a document is integrated within the document on the right.
Similar functionality will be available in Office Communications Server 2010 due out 2H 2010.
Microsoft Skydrive allows users to create Word, Excel, PowerPoint and OneNote documents at no cost. The features are significantly scaled down, and co-authoring is not possible with these free versions, whereas Google Docs includes co-authoring. Microsoft will need to add co-authoring to Skydrive to compete with Google.
System Requirements for Co-Authoring
- Microsoft SharePoint Foundation 2010 or Microsoft SharePoint Server 2010
- Word 2010, PowerPoint 2010, OneNote 2010
- Excel Web App requires a volume license agreement as described above.