Strictly OOXML for Office 2013 says Microsoft
Microsoft has announced that it will, for the first time, support the strict version of its "Open XML" standard in Office 2013. It will join new ODF 1.2 and PDF support in Microsoft's office suite.
Open XML, also known as OOXML (ISO/IEC 29500), was regarded by many as Microsoft's spoiler to the progress of the Open Document Format (ISO/IEC 26300) standard. In 2005, ODF was put forward as an ISO standard by OASIS and was moving rapidly through the ISO process. In November of the same year, Microsoft announced it was working on its own "Office Open XM" standard with ECMA, which was later fast tracked to the ISO in what was a contentious and fraught process.
In the end, both Open XML and ODF were standardised by the ISO, but Microsoft didn't switch to supporting "Strict" Open XML, working instead with a version of the standard called "Transitional" Open XML. This version of the standard was designed to be used on a temporary basis while the company switched over to the ISO-approved OOXML and pulled in a number of legacy elements such as VML (Vector Markup Language) to ensure compatibility. Microsoft pushed back its plans to switch, releasing Office 2007 without support for it and Office 2010 with only the ability to open and edit, not save, Strict OOXML documents.
Even then, the OOXML standard was being criticised by experts who had shepherded the specification through the ISO process. Microsoft's delay in deploying Strict OOXML also meant that software like OpenOffice and LibreOffice had to reverse engineer the legacy elements of Transitional OOXML.
With Office 13, Microsoft will fully support its own OOXML standard a full five years after it was approved by international standards bodies. With the move to support Strict OOXML, it should be much easier for developers to implement and interoperate with the Microsoft-created ISO standard.
Microsoft previously announced it was going to support ODF 1.2 in Office 2013. ODF 1.2 was approved in October 2011 and added standardised support for spreadsheet formulas. According to the Microsoft blog post, the addition of ODF 1.2 open/edit/save support will also see the end of the ability to save ODF 1.1 documents, though it will still be possible to open and edit them.
Another ISO standard getting support in Office 2013 is ISO 32000, the PDF standard. However, Microsoft's Tristan Davis has explained that this support is predominantly aimed at giving Word users the ability to load PDF documents and transform them back into Word documents, rather than being a PDF viewer or editor. Office users can already save to PDF format.