Open standards are widely considered to have significant economic and technological benefits. This has led many governments to consider mandating open standards for document formats. Document formats are how a computer stores memos or spreadsheets. Governments are moving away from Microsoft’s proprietary DOC format to open standard document formats, such as the OpenDocument Format (ODF) and Office Open XML (OOXML). The belief is that by shifting to open standards, governments will benefit from choice, competition, and the ability to seamlessly substitute different vendor implementations.

This paper suggests that governments seeking the benefits of open standards need to consider the role of interoperability. Without multiple interoperable implementations, i.e., “running code”, users will not gain the advantages of competition and substitutability. To highlight the issues around interoperability, we examined the interoperability issues around ODF and OOXML.

This research assesses interoperability among different software implementations of each document formats. For example, the implementations for ODF included KOffice, Wordperfect, TextEdit, Microsoft Office, and Google Docs. A set of test documents was used to evaluate the performance of other alternative implementations.

Our analyses show that there are significant issues with interoperability among various implementations. Users face numerous issues when transferring files between different implementations. While the best implementations may result in formatting problems, the worst implementations actually lose information, e.g., information found in pictures, footnotes, comments, tracking changes, and tables. Our findings include specific scores for each implementation. There was considerable variation among how well each implementation performed. For ODF, the compatibility scores ranged from a raw score of 151 (100%--weighted percent) to 48 (55%--weighted percent).

We consider several implications of these results including the lack of perfect compatibility between implementations, the lack of good implementations outside of Windows, and the surprisingly good overall performance of OOXML implementations. The interoperability issues are troubling and suggest the need for improved interoperability testing for document formats. The results also highlight the importance of interoperability for open standards in general. Without interoperability, governments will be locked-in to the dominant implementations for either standard and in the process lose many of the benefits that might accrue from adopting an open standard in the first instance.


Law and Economics

Date of this Version

July 2008