10. Excel: Multiple Editors

Excel Web is the only Office Web app with co-authoring features at this point, and while sharing the document and making changes is very easy, managing what’s going on is much less simple. The pop-up menu at the bottom of the screen shows the email addresses of everyone working in the document, but it doesn’t let you email or instant message them. When someone has made a change the word "Working" appears in the status bar and this is the only indication that you have that something is going to change somewhere in the document. You don’t get the colored outlines you see in a Google Docs spreadsheet, so you don’t know which cells to avoid. You’ll need to decide in advance who is doing what, otherwise you can type in the same place as a co-author. Also, when you have multiple authors, you don’t have access to a "undo" or "redo" menu option.