While there is a way for you to open two Excel workbooks at the same time, you can also open multiple spreadsheets in separate windows. Learn how!

How to Open Excel 2007 Files As Separate Windows. If you work with multiple Excel files over the course of a workday, and especially if you use a dual-monitor setup, you might wonder how you can ...

These free add-ins for Word, Excel, and PowerPoint enable those apps to open and save their ODF counterparts (which typically have .ODT, .ODS, and .ODP extensions, respectively).