File type specification: Microsoft Office file type.
The xlsm file extension is associated with Microsoft Excel, one of the most popular and powerful tool you can use to create format spreadsheets, graphs and much more.
The *.xlsm files are used in Microsoft Excel 2007, 2010, 2013, 2016 for Workbooks, spreadsheet document files. They serve the same purpose as the .xlsx Microsoft Excel Open XML workbook files, but also contain additional macros and VBA scripts.
The files also use the new file extensions and file formats for Excel Spreadsheets based on Open XML data format. The *.xlsm files use ZIP compression for smaller file sizes.
MIME: application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
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