| Format introduction | The Office Open XML file formats are a set of file formats that can be used to represent electronic office documents. There are formats for word processing documents, spreadsheets and presentations as well as specific formats for material such as mathematical formulae, graphics, bibliographies etc. |
| Technical details | Office Open XML documents are stored in Open Packaging Convention (OPC) packages, which are ZIP files containing XML and other data files, along with a specification of the relationships between them. Depending on the type of the document, the packages have different internal directory structures and names. |
| File extension | .xlsx, .xlsm |
| MIME | application/vnd.openxmlformats-officedocument.spreadsheetml.sheet |
| Developed by | Microsoft |
| Type of format | Spreadsheet |
| Associated programs | Microsoft Office, LibreOffice, Kingsoft Office, Google Docs. |
| Wiki | https://en.wikipedia.org/wiki/Office_Open_XML_file_formats |