Spreadsheet Compare (Excel compare) is a Microsoft Excel Add-In, written in VBA, that performs a cell-by-cell comparison of Worksheets within the same or different Workbooks. Requires Excel 2000 or later.
The best way to see all the features is to view the online help.
Here is the Spreadsheet Compare Add-In ribbon:
Online help is available here.
Spreadsheet Compare Add-In is hosted by: