How to convert xlsx files to xls or csv format on Linux

The xlsx file name extension is a new file format based on XML, used by Microsoft Office Excel 2007 spreadsheet application. The letter "x" appended to the existing "xls" extension used by earlier versions of Excel, signifies that the format is based on XML. If you would like to open or edit an xlsx file created by Excel 2007, on an earlier version of Excel or any other spreadsheet application, you need to convert xlsx files first.Read more »