From the article:
The irony here is that the formula language used by OpenOffice (and by other vendors) is based on that used by Excel, which itself was not fully documented when OpenOffice implemented it. So an argument, by Microsoft, not to support that language because it is not documented is rather hypocritical. Excel supports 1-2-3 files and formulas and legacy Excel versions (back to Excel 4.0) neither of which have standardized formula languages. Why are these supported? Also, the fact that the Microsoft/CleverAge add-in correctly reads and writes the legacy ODF formula syntax shows not only that it can be done, but that Microsoft already has the code to do it. The inexplicably thing is why that code never made it into Excel 2007 SP2.