You don't necessarily need Microsoft Excel to work with an .xlsx file Reviewed by Ryan Perian This article explains what XLSX ...

Although Calc can't save to the new .xlsx file extension, you can use a combination of Calc and Excel to perform the final conversion. Convert the spreadsheet to a basic version of Microsoft Excel ...

Google can convert a Microsoft Excel workbook to a ... Java gives you the ability to dynamically... Converting your XLSX file to a Google spreadsheet will not overwrite the original file.