.GNM File Extension
File TypeGnumeric Spreadsheet
What is a GNM file?
Spreadsheet file created by Gnumeric, an open source spreadsheet application developed by the GNOME Project; stores formatting information, charts, and other data used in the spreadsheet; similar to Excel spreadsheet files (.XLSX), both containing data stored in the XML format; compressed using GZIP compression.
NOTE: GNM files are also commonly saved with the .GNUMERIC file extension.