Microsoft's embattled Office Open XML (OOXML) document format received ISO fast-track approval today after receiving support from approximately 86 percent of the national bodies that participated in the vote. ISO approval will be broadly perceived as a sign of validation for the document format which has received widespread criticism from technical experts and standards advocacy groups.

Failure to obtain ISO approval would have put Microsoft at a disadvantage in government software procurement processes which are increasingly mandating or favoring open standards. The trend towards standards adoption in government IT could have potentially pushed the public sector away from Microsoft's deeply entrenched office offerings and towards a variety of alternatives like OpenOffice.org which uses the ISO-approved OpenDocument Format (ODF). ISO's approval of OOXML—the default format in Office 2007—will help Microsoft remain competitive in the government software market.

OOXML was approved as an ECMA standard in 2006 but failed to achieve ISO approval during an initial 2007 vote. ISO's second fast-track vote, which took place earlier this month, delivered a sufficient number of votes in favor of the format to move forward with ISO approval. The process has received heavy scrutiny from critics who claim that Microsoft has engaged in abusive practices ranging from committee-stuffing to potential vote buying. Critics have documented some evidence of various irregularities in national body internal voting processes in Russia, Poland, Mexico, Sweden, Germany, and other countries.

Microsoft refutes the allegations and argues that ISO's first vote on OOXML failed to pass solely because of IBM's intervention, a claim that IBM rejects.

A recent ballot resolution meeting was conducted to address the numerous problems that the ISO national bodies have found in the OOXML specification. During the meeting, ISO participants were to evaluate 2,300 pages of ECMA responses to criticisms of the 6,000-page OOXML specification. Due to time constraints, only a fraction of the responses were addressed, leading many to argue that the format was unsuited for fast-track approval.

Although OOXML has many critics, it was also gained numerous supporters over the past year—including some who are directly affiliated with ODF. One of the most outspoken OOXML supporters from the ODF camp is Patrick Durusau, a coeditor of the ODF specification. Durusua characterizes OOXML as a "poster child for the open standards development process" and argues that ECMA has been instrumental in facilitating needed changes to an extent that makes it suitable for ISO approval. Durusau has called for standards advocates to "foster coevolution" between OOXML and ODF in order to encourage more interoperability.

Regardless of OOXML's ISO status, the format will inevitably become a de facto industry standard as a result of the market dominance of Microsoft's office suite. Microsoft says that ISO approval will place the future of the format in the hands of the standards community, but critics point to Microsoft's long history of outright hostility towards open standards and fear that others will have little say in how OOXML evolves.