Disputes over ODF spreadsheet interoperability

Microsoft's release of Open Document Format (ODF) support in Service Pack 2 for Office 2007 has triggered a war of words over the handling of spreadsheet formulas. Rob Weir has posted the results of his interoperability testing of various applications which claim ODF compatibility. Weir's results show Microsoft ODF support as failing on spreadsheet tests with nearly all other applications.

The core of the problem is the storage of spreadsheet formulas within a spreadsheet. The ODF specifications published to date – 1.0 and 1.1, do not specify a format for this element, but allow for a cached value and use prefixes to describe the particular formula formats. The ODF 1.2 specification will use another standard, Open Formula, currently in development, to achieve interoperability for formulas, and the OpenOffice developers have already implemented ODF 1.2 and Open Formula support.

However, Microsoft have stuck to the published ODF 1.1 specification. They have not implemented Open Formula, says Microsoft's Doug Mahugh because it is not a final standard. This means in practice, that a spreadsheet generated in OpenOffice 3.x and imported into Excel will silently drop the formulas from cells and only use the cached value. Microsoft has also used its own "msoxl" prefix for formulas from Excel spreadsheets, which means that when a Excel spreadsheet is saved as ODF and imported into OpenOffice, the formulas appear as strings. Mahugh points out that importing a OpenOffice 3.0 spreadsheet into Symphony 1.2 gives a similar effect except with "of" as the prefix. In response Wier says that Symphony 1.3 beta does handle OpenOffice 3.0 spreadsheets correctly. Mahugh has countered that by asking why the beta version of Kspread wasn't included in Weir's testing as that handles the "msoxl" prefix correctly.

The issue of spreadsheet formulas has been discussed since 2005, when it was noted that the lack of a standard may cause problems with interoperability.

(djwm)