Can two or more people edit an Excel document at the same time?
I have a SharePoint 2010 site with a document library for storing Excel files. If someone is editing an Excel file (using stand-alone Excel, not Excel services), everyone else will be forced to open the file read-only until the first person is done editing. Is there a way around this? What I want is to allow two or more people to be able to edit the file at the same time. Also, I don't want people to overwrite each other. Instead, I'd like SharePoint to merge their changes. Is this possible in SharePoint 2010?
Answer
No, sadly:
The Excel 2010 client application does not support co-authoring workbooks in SharePoint Server 2010. However, the Excel client application does support non-real-time co-authoring workbooks stored locally or on network (UNC) paths by using the Shared Workbook feature. Co-authoring workbooks in SharePoint is supported by using the Microsoft Excel Web App, included with Office Web Apps
From Co-authoring overview (SharePoint Server 2010)
...and not for SharePoint 2013 either. Though it works for pretty much all other Office documents. Go figure.