IBM colleague and standards activist Rob Weir tested compatibility of the free ODF documentation standard in different combinations with various office software. His conclusion: "This is a big step backwards." In a similar test beginning of March, Weir had come to more positive results, albeit with some recommendations, mainly because he had used the Sun plugin and Microsoft's own CleverAge to populate the Excel cells. In the meantime, Microsoft released MS Office 2007 SP2 that was supposed to support ODF.

So Weir tested again, this time with MS Office 2007 SP2 with integrated ODF support, and he wasn't too happy with the results. He writes in his blog, "Unfortunately this support did not fare well in my tests." Weir found that Excel SP2 stripped out formulas, leaving the previously saved values. He concluded, "In general, SP2 converts an ODF spreadsheet into a mere 'table of numbers' and any calculation logic is lost."

ODF data in Excel after conversion.

Even table formulas exported from Excel to ODF spreadsheets presented problems. "Excel 2007 SP2 does include spreadsheet formulas but places them into an Excel namespace. This namespace is not what OpenOffice and other ODF applications use... It isn't even the OOXML namespace."

Weir's disappointment contrasts sharply with his hopefulness two months ago. In his view, technical complexity can't be the problem: "Spreadsheet interoperability is not hard. This is not rocket science... To get this wrong requires more effort than getting it right. It is especially frustrating when we know that the underlying applications support the same fundamental formula language, or something very close to it...." He doesn't want to speculate whether this is accidental or intentional, but encouraged Microsoft to remove the code from SP2 that was the source of the problem. "... I cannot fail to notice that the same application -- Microsoft Excel 2007 -- will process ODF spreadsheet documents without problems when loaded via the Sun or CleverAge plugins, but will miserably fail when using the 'improved' integrated code in Office 2007 SP2."