More details are emerging about the ODF converter which will be in Office 2007 SP2, set for release next year. Doug Mahugh’s post outlines the architecture and explains how the converter will deal with compatibility issues.

I want to highlight the section that describes how the converter is implemented:

Word, Excel and PowerPoint have a Model-View-Controller design. The in-memory representation of the document, or Model, is designed to facilitate document revision and display functions and includes concepts which are never saved to the file, such as the insertion point and the selection.

The persistence code converts this in-memory representation to and from some sort of the disk file based representation. Office 2007 already had code to support a number of angle-brackety persistence formats including HTML and OOXML. When we built in support for ODF, we added it in that area of our code.

That suggests deep integration, and a converter that has good chances of working smoothly and quickly – unlike the clunky open source translator which Microsoft sponsored, which is based on XSLT.

Users also have the option of Sun’s plug-in, which is based on Open Office code.

It seems that Microsoft is aiming to make Office 2007 a good ODF citizen. Will that impede adoption of Microsoft’s own OOXML format? Well, I guess OOXML will still be the default, and will have the best support for Office-specific features. Another thing to bear in mind is that OOXML was designed with Office specifically in mind. Potentially troublesome creatures like very large Excel spreadsheets may well perform best with OOXML. Another point is that Microsoft’s server products, where they exploit XML documents, are likely to work best with OOXML. In other words, there are likely to be advantages in OOXML within enterprises that use Microsoft’s platform.

Still, strong support for ODF by default in Office will be a significant boost for the OASIS format. Microsoft is protecting its very profitable Office sales against the risk of being dropped for lack of ODF compatibility.