Office Open XML

Office Open XML Document
The OOXML Document icon, as appears on the Microsoft OneDrive web service
Filename extension
.docx, .docm
Internet media type
application/vnd.
openxmlformats-officedocument.
wordprocessingml.
document
Developed byMicrosoft, Ecma, ISO, IEC
Initial release7 December 2006 (2006-12-07)
Latest release
4th edition
26 October 2016 (2016-10-26)
Type of formatDocument file format
Extended fromXML, DOC, WordProcessingML
StandardECMA-376, ISO/IEC 29500
Open format?Yes
WebsiteECMA-376, ISO/IEC 29500-1:2016
Office Open XML Presentation
Filename extension
.pptx, .pptm
Internet media type
application/vnd.
openxmlformats-officedocument.
presentationml.
presentation
Developed byMicrosoft, Ecma, ISO, IEC
Initial release7 December 2006 (2006-12-07)
Latest release
3rd edition
29 June 2011 (2011-06-29)
Type of formatPresentation
Extended fromXML, PPT
StandardECMA-376, ISO/IEC 29500
Open format?Yes
WebsiteECMA-376, ISO/IEC 29500:2016
Office Open XML Workbook
Filename extension
.xlsx, .xlsm
Internet media type
application/vnd.
openxmlformats-officedocument.
spreadsheetml.
sheet
Developed byMicrosoft, Ecma, ISO, IEC
Initial release7 December 2006 (2006-12-07) (as Microsoft Open XML)
Latest release
3rd edition
29 June 2011 (2011-06-29)
Type of formatSpreadsheet
Extended fromXML, XLS, SpreadsheetML
StandardECMA-376, ISO/IEC 29500
Open format?Yes
WebsiteECMA-376, ISO/IEC 29500:2016

Office Open XML (also informally known as OOXML) is a zipped, XML-based file format developed by Microsoft for representing spreadsheets, charts, presentations and word processing documents. Ecma International standardized the initial version as ECMA-376. ISO and IEC standardized later versions as ISO/IEC 29500.

Microsoft Office 2010 provides read support for ECMA-376, full support for ISO/IEC 29500 Transitional, and read support for ISO/IEC 29500 Strict. Microsoft Office 2013 and later fully support ISO/IEC 29500 Strict, but do not use it as the default file format because of backwards compatibility concerns.