Office Open XML explained

Office Open XML (also informally known as OOXML)[1] 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.[2] Microsoft Office 2013 and later fully support ISO/IEC 29500 Strict,[3] but do not use it as the default file format because of backwards compatibility concerns.[4]

Background

In 2000, Microsoft released an initial version of an XML-based format for Microsoft Excel, which was incorporated in Office XP. In 2002, a new file format for Microsoft Word followed.[5] The Excel and Word formats—known as the Microsoft Office XML formats—were later incorporated into the 2003 release of Microsoft Office.

Microsoft announced in November 2005 that it would co-sponsor standardization of the new version of their XML-based formats through Ecma International as "Office Open XML".[6] [7] The presentation was made to Ecma by Microsoft's Jean Paoli and Isabelle Valet-Harper.[8] [9]

Standardization process

See main article: Standardization of Office Open XML.

Microsoft submitted initial material to Ecma International Technical Committee TC45, where it was standardized to become ECMA-376, approved in December 2006.[10]

This standard was then fast-tracked in the Joint Technical Committee 1 of ISO and IEC. After initially failing to pass, an amended version of the format received the necessary votes for approval as an ISO/IEC Standard as the result of a JTC 1 fast-tracking standardization process that concluded in April 2008.[11] The resulting four-part International Standard (designated ISO/IEC 29500:2008) was published in November 2008[12] and can be downloaded from the ITTF.[13] A technically equivalent set of texts is published by Ecma as ECMA-376 Office Open XML File Formats—2nd edition (December 2008); they can be downloaded from their website.[14]

The ISO/IEC standardization of Office Open XML was controversial and embittered,[15] with much discussion both about the specification and about the standardization process.[16] According to InfoWorld, "OOXML was opposed by many on grounds it was unneeded, as software makers could use OpenDocument Format (ODF), a less complicated office software format that was already an international standard." The same InfoWorld article reported that IBM (which supports the ODF format) threatened to leave standards bodies that it said allow dominant corporations like Microsoft to wield undue influence. The article further says that Microsoft was accused of co-opting the standardization process by leaning on countries to ensure that it got enough votes at the ISO/IEC for Office Open XML to pass, although it does not specify exactly who accused Microsoft.

Licensing

Under the Ecma International code of conduct in patent matters,[17] participating and approving member organizations of ECMA are required to make their patent rights available on a reasonable and non-discriminatory (RAND) basis.

Holders of patents which concern ISO/IEC International Standards may agree to a standardized license governing the terms under which such patents may be licensed, in accord with the ISO/IEC/ITU common patent policy.[18]

Microsoft, the main contributor to the standard, provided a covenant not to sue[19] for its patent licensing. The covenant received a mixed reception, with some like the Groklaw blog criticizing it,[20] and others such as Lawrence Rosen, (an attorney and lecturer at Stanford Law School), endorsing it.[21]

Microsoft has added the format to their Open Specification Promise[22] in which

Microsoft irrevocably promises not to assert any Microsoft Necessary Claims against you for making, using, selling, offering for sale, importing or distributing any implementation to the extent it conforms to a Covered Specification [...]

This is limited to applications which do not deviate from the ISO/IEC 29500:2008 or Ecma-376 standard and to parties that do not "file, maintain or voluntarily participate in a patent infringement lawsuit against a Microsoft implementation of such Covered Specification".[23] [24] The Open Specification Promise was included in documents submitted to ISO/IEC in support of the ECMA-376 fast-track submission.[25] Ecma International asserted that, "The OSP enables both open source and commercial software to implement [the specification]".[26]

Versions

The Office Open XML specification exists in several versions.

ECMA-376 1st edition (2006)

The ECMA standard is structured in five parts to meet the needs of different audiences.

Part 1. Fundamentals
Part 2. Open Packaging Conventions
Part 3. Primer
Part 4. Markup Language Reference
Part 5. Markup Compatibility and Extensibility

Later versions of the ECMA-376 standard are aligned and technically equivalent to the corresponding ISO standard.

ISO/IEC 29500:2008

The ISO/IEC standard is structured into four parts:[27] Parts 1, 2 and 3 are independent standards; for example, Part 2, specifying Open Packaging Conventions, is used by other file formats including XPS and Design Web Format. Part 4 is to be read as a modification to Part 1, which it requires.

A technically equivalent set of texts is also published by Ecma as ECMA-376 2nd edition (2008).

Part 1. Fundamentals & Markup Language Reference
  • Consisting of 5560 pages, this part contains:
    Part 2. Open Packaging Conventions
  • Consisting of 129 pages, this part contains:
    Part 3. Markup Compatibility and Extensibility
  • Consisting of 40 pages, this part contains:
    Part 4. Transitional Migration Features
  • Consisting of 1464 pages, this part contains:

    The standard specifies two levels of document & application conformance, strict and transitional, for each of WordprocessingML, PresentationML and SpreadsheetML, and also specifies applications' descriptions of base and full.

    Compatibility between versions

    The intent of the changes from ECMA-376 1st Edition to ISO/IEC 29500:2008 was that a valid ECMA-376 document would also be a valid ISO 29500 Transitional document;[28] however, at least one change introduced at the BRM—refusing to allow further values for xsd:boolean—had the effect of breaking backwards-compatibility for most documents.[29] A fix for this had been suggested to ISO/IEC JTC 1/SC 34/WG 4, and was approved in June 2009 as a recommendation for the first revision to Office Open XML.[30]

    Applications capable of reading documents compliant to ECMA-376 Edition 1 would regard ISO/IEC 29500-4 Transitional documents containing ISO 8601 dates as corrupt.[31]

    Application support

    See main article: List of software that supports Office Open XML. Some older versions of Microsoft Word and Microsoft Office are able to read and write .docx files after installation of the free compatibility pack provided by Microsoft,[32] although some items, such as equations, are converted into images that cannot be edited.[33]

    Starting with Microsoft Office 2007, the Office Open XML file formats have become the default file format[34] of Microsoft Office.[35] [36] However, due to the changes introduced in the Office Open XML standard, Office 2007 is not wholly in compliance with ISO/IEC 29500:2008.[37] Office 2010 includes support for opening documents of the ISO/IEC 29500:2008-compliant version of Office Open XML, but it can only save documents conforming to the transitional, not the strict, schemas of the specification.[38] [39] Note that the intent of the ISO/IEC is to allow the removal of the transitional variant from the ISO/IEC 29500 standard.[39] Microsoft Office 2013 and later fully support ISO/IEC 29500 Strict,[40] but do not use it as the default file format because of backwards compatibility concerns.[41]

    The ability to read and write Office Open XML format is, however, not limited to Microsoft Office; other office products are also able to read & write this format:

    Other office products that offer import support for the Office Open XML formats include:

    See also

    Further reading

    External links

    Notes and References

    1. Web site: The Document Foundation, LibreOffice and OOXML. 2016-03-22. The Document Foundation.
    2. Web site: Overview of the XML file formats in Office 2010 . Office 2010 Resource Kit . Microsoft . 5 August 2011.
    3. Web site: XML file name extension reference for Office 2013 . Office 2013 Resource Kit . Microsoft . 26 December 2016 .
    4. Web site: XLSX Strict (Office Open XML), ISO 29500-1:2008-2016. Library of Congress. 2018-09-09.
    5. Web site: Brian Jones. 2007-01-25. History of office XML formats (1998–2006). 2020-12-31. MSDN blogs.
    6. Web site: Microsoft Co-Sponsors Submission of Office Open XML Document Formats to Ecma International for Standardization . Microsoft . 2005-11-21.
    7. https://ssrn.com/abstract=1656616 Casson and Ryan, Open Standards, Open Source Adoption in the Public Sector, and Their Relationship to Microsoft’s Market Dominance
    8. https://www.cnet.com/news/microsoft-hands-over-office-xml-specs-to-ecma/ Microsoft hands over Office XML specs to Ecma
    9. Web site: Slides presented by the TC45 committee to Ecma International . 2011-06-08 . https://web.archive.org/web/20111021022009/http://www.ecma-international.org/activities/Office%20Open%20XML%20Formats/TC45_GA_Dez05.pdf/ . 2011-10-21 . dead .
    10. Web site: Ecma International approves Office Open XML standard . Ecma International . 2006-12-07.
    11. Web site: ISO/IEC DIS 29500 receives necessary votes for approval as an International Standard . 2008-04-02 . ISO.
    12. Web site: Publication of ISO/IEC 29500:2008, Information technology—Office Open XML formats . 2008-11-18 . 2008-11-19 . ISO . ISO/IEC . 2009-07-06 . https://web.archive.org/web/20090706154539/http://www.iso.org/iso/pressrelease.htm?refid=Ref1181 . dead .
    13. Web site: Freely Available Standards . ITTF (ISO/IEC) . 2008-11-18 . 2023-09-26 .
    14. Web site: Standard ECMA-376 . Ecma-international.org . 2009-05-19 .
    15. News: Kirk . Jeremy . ISO publishes Office Open XML specification . . 19 November 2008 . 12 June 2010.
    16. Web site: Norwegian standards body implodes over OOXML controversy . 3 October 2008 . Ars Technica.
    17. Web site: Code of Conduct in Patent Matters . Ecma International.
    18. Web site: ISO/IEC/ITU common patent policy.
    19. Web site: Microsoft's Open Specification Promise Eases Web Services Patent Concerns. . September 12, 2006 . 2015-04-18 .
    20. Web site: 2 Escape Hatches in MS's Covenant Not to Sue . December 4, 2005 . Groklaw.
    21. Web site: Top open source lawyer blesses new terms on Microsoft's XML file format . David . Berlind . November 28, 2005 . 2007-01-27 . ZDNet .
    22. Web site: Microsoft Open Specification Promise . Microsoft . 2007-02-15 . 2015-04-18 .
    23. Web site: Ecma formal publications . Ecma International. Ecma Standards and Technical Reports are made available to all interested persons or organizations, free of charge and licensing restrictions.
    24. Web site: Microsoft Open Specification Promise . Microsoft.com.
    25. Web site: Licensing conditions that Microsoft offers for Office Open XML . Jtc1sc34.org . 2006-12-20 . 2009-05-19.
    26. Web site: Microsoft Word — Responses to Comments and Perceived Contradictions.doc . 2009-09-16.
    27. Web site: ISO search for "29500". International Organization for Standardization. 2009-06-05.
    28. Web site: Re-introducing on/off-values to ST-OnOff in OOXML Part 4. 2009-09-29. 2009-06-26. https://web.archive.org/web/20090626065627/http://idippedut.dk/post/2009/06/23/Re-introducing-onoff-values-to-ST-OnOff-in-OOXML-Part-4.aspx. dead.
    29. Web site: OOXML and Office 2007 Conformance: a Smoke Test. 2009-09-29. https://web.archive.org/web/20100428091855/http://www.adjb.net/post/OOXML-and-Office-2007-Conformance-a-Smoke-Test.aspx. 2010-04-28. dead.
    30. Web site: Minutes of the Copenhagen Meeting of ISO/IEC JTC1/SC34/WG4. 2009-06-22. 2009-09-29. https://web.archive.org/web/20140512224125/http://kikaku.itscj.ipsj.or.jp/sc34/open/1239.pdf. 2014-05-12. dead. page 15
    31. Web site: ISO/IEC 29500-4:2008/Draft Amd2:2011 - Draft - Information technology — Document description and processing languages — Office Open XML File Formats — Part 4: Transitional Migration Features - AMENDMENT 2 . PDF . 2011-03-02 . 2011-04-04 . https://web.archive.org/web/20140512232105/http://kikaku.itscj.ipsj.or.jp/sc34/wg4/archive/sc34-wg4-2011-0173.zip . 2014-05-12 . dead .
    32. Web site: Microsoft Office Compatibility Pack for Word, Excel, and PowerPoint 2007 File Formats (Version 3). Microsoft. 2007-06-18. 2018-06-23.
    33. http://office.microsoft.com/en-us/word-help/open-a-word-2007-document-in-an-earlier-version-of-word-HA010044473.aspx Open a Word 2007 document in an earlier version of Word - Word - Office.com
    34. Web site: Microsoft Expands List of Formats Supported in Microsoft Office . Microsoft . 2008-05-21 .
    35. Web site: Microsoft's future lies somewhere beyond the Vista by Evansville Courier & Press . Courierpress.com . 2009-05-19 . 2014-07-10 . https://web.archive.org/web/20140710192710/http://www.courierpress.com/news/2008/oct/24/microsofts-future-lies-somewhere-beyond-the/ . dead .
    36. Web site: Rivals Set Their Sights on Microsoft Office: Can They Topple the Giant? - Knowledge@Wharton . Knowledge.wharton.upenn.edu . 2009-05-19.
    37. Web site: Andy Updegrove . Microsoft Office 2007 to Support ODF — and not OOXML . 21 May 2008 . ConsortiumInfo.org . 2009-05-19 . 2008-05-23 . https://web.archive.org/web/20080523233233/http://www.consortiuminfo.org/standardsblog/article.php?story=20080521092930864 . dead .
    38. Web site: ISO OOXML convener: Microsoft's format "heading for failure" . 2 April 2010 . Ars Technica.
    39. Web site: Microsoft Fails the Standards Test . Where is an end of it? . Brown . Alex . Alex Brown's weblog . 31 March 2010 . 23 June 2018.
    40. Web site: XML file name extension reference for Office 2013 . Office 2013 Resource Kit . Microsoft . 26 December 2016 .
    41. Web site: XLSX Strict (Office Open XML), ISO 29500-1:2008-2016. Library of Congress. 2018-09-09.
    42. Web site: 2 November 2020. Collabora Online 6.4.0-released.
    43. Web site: LibreOffice OOXML. 22 March 2012.
    44. Web site: OpenOffice.org 3.0 New Features. 2008-10-13. 2009-10-24.
    45. Web site: OpenOffice.org 3.2 New Features. 2010. 2010-11-13.
    46. Web site: OpenOffice 3.2 - now with less Microsoft envy. Scott Gilbertson. 13 February 2010. 18 Feb 2013. The Register. the ability to open password-protected Word, Excel, and PowerPoint files.
    47. Web site: 3.2.0 (build OOO320_m12) - Release Notes. 18 Feb 2013. Import of password protected Microsoft Office XML files .