The editor of the Open Document Format (ODF) standard has written a letter that strongly supports recognizing Microsoft's Open Office XML (OOXML) file format as a standard, arguing that if it fails, ODF will suffer.

"As the editor of OpenDocument, I want to promote OpenDocument, extol its features, urge the widest use of it as possible, none of which is accomplished by the anti-OpenXML position in ISO," Patrick Durusau wrote. "The bottom line is that OpenDocument, among others, will lose if OpenXML loses. ... Passage of OpenXML in ISO is going to benefit OpenDocument as much as anyone else."

Members of the International Organization for Standardization (ISO) are considering whether to recognize OOXML as a standard. Critics of the specification have said it is too proprietary to be rightly considered a standard. The cutoff date for participating countries to vote on the standard is March 29.

The letter's support of OOXML is more explicitly worded than a previous one Durusau wrote, calling for the two sides to work together.

But Durusau argued in his open letter that nothing will be gained if the ISO shoots down OOXML.

"OpenDocument currently lacks formula definitions for spreadsheets," he wrote. "Many core financial functions in spreadsheets are undefined except for actual Excel output. That output varies by version and service pack of MS Office. What happens if OpenDocument and OpenXML reach different definitions of those functions?"

In addition, ODF doesn't yet support "legacy features of Microsoft formats," he added. "That will be easier with a formal definition of those features."

Also, Durusau said, "OpenDocument does not have a robust mapping to the current Microsoft format. That requires an OpenXML that has completed the standards process."