In discussions about Open XML one of the questions I get asked most frequently is one that was originally presented by noooxml.org and our colleagues at a large and well known competitor. “We already have an international standard for document formats, why do we need another?”
The answer is a straight forward one, Open XML has different design objectives to other document standards, those differences are defined in the first few paragraphs of the Office Open XML specification.
- Open XML provides for the migration of existing Microsoft Office binary documents to the new XML format, providing new levels of transparency and access to existing data.
- Open XML provides a mechanism for the use of Custom XML schema as part of the document format.
When you look at those two unique requirements the first is backwards looking, protecting the huge existing investment in binary documents, the second requirement is not only very forward looking, but for the developer community it is probably one of the most exciting features of the Office Open XML specification.
I’ve talked a little before about custom schema in Open XML, but only recently realized that it was not obvious what this unique proposition is that is offered by the Ecma-376 specification.
Two weeks ago I was in Beijing where I was presenting at an international standards conference organized by OASIS, I was presenting on Open XML and how Microsoft proposed to interoperate with the Open Document Format and the Chinese office document standard, the Uniform Office Format.
After my presentation I found myself chatting to a well known blogger in the standards and open document space, and as part of the conversation he and I were discussing the difference between ODF and Open XML at a very conceptual level. He drew a diagram on a piece of paper that looked a little like the graphic below, personally I think it gives a very clear picture of the role that custom schema plays, one of the key differences between Open XML and ODF, and how the two document formats could interoperate in the longer term.
The graphic talks about the role that Office Open XML compliant applications have in wider business processes within an organization, moving well beyond the traditional office automation file format that we have all become used to over the last twenty or so years. It also shows how converter technology will assist users of the ODF file format (along with other file formats) who want to convert their documents to Open XML or vice versa.
The same applies to UOF for which conversion tools between Open XML and UOF already exist, the Beijing event was a great opportunity to demonstrate this additional converter to a few people working in this space in China.