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Office Open XML standardization

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Office Open XML (OOXML) is a document format which has been standardized by the European Computer Manufacturers Association (ECMA). It has been submitted to the International Standardization Organization (ISO) as ISO/IEC DIS 29500.

OOXML has been drafted by Microsoft as a feature mapping standard between legacy Office formats and new XML files. The purpose of the standard is to provide an easy interface to import old binary files and to map them to the features of modern, XML based file formats such as ISO 26300 (Open Document Format).

Problems of the proposal

Office Open XML comes with a 6'000 page specification, covering the various formats included. However, a large portion of the specification is made up by definitions of formats for which open standard formats already exist, for example the MathML markup language, specified by the World Wide Web Consortium (W3C).

Also, the ISO/IEC DIS 29500 standard proposal contains various violations of good XML coding practices. For example, bitmasks are used in various places instead of boolean flags, which are standard practice in other XML formats. The advantage of using boolean flags is of course that files in the resulting format can be converted easily to different XML formats using an XSLT style sheet. With OOXML files, this is simply not possible.

Finally, the specification also contains various outright bugs, some of which have been put into it consciously in order to maintain bug compatibility of the standard with prior versions of Microsoft specific products. For example, a calendar system is used which has various shortcomings. First of all, it introduces the nonexistent January 1st, 1900 – a day which has never happened. Also, the format does not provide a way to specify dates before January 1st, 1900 – a huge shortcoming, since a lot of users will want to specify dates before January 1st, 1900.

Last but not least, there is a patent issue involved with implementing the OOXML specification. In order to be able to convert OOXML files faithfully to other formats, the entire 6'000 page specification will have to be implemented, including all optional parts. However, Microsoft's convenant not to sue only covers the required parts of OOXML, thus excluding parts which are declared optional although they are indeed very important to teh end user, and the referenced file format specifications, some of which are also required to implement the document format.

With all of these shortcomings, there is sufficient reason to redraft OOXML witout the bugs and to resolve the patent issues, potentially through the use of open standards. The latter would also kill a lot of bugs and obstacles to compatibility and accessibility, because the open standard formats have been drafted by experts from all these areas. There is no reason whatsoever not to make use of this work.

A summary of the precise problems discovered can be found in the papers section.


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