Why open file formats are best

You go to a lot of effort to make sure that your data is secure, both in the sense that only the right people can get at it and making indestructible. What if I told you that all of the data you have stored will one day be completely unreadable.

Sounds unlikely? To prove my point I only have to give you a reel of one inch magnetic tape which was the standard storage medium less than 40 years ago. You can’t read it now unless you go to a lot of trouble to find a suitable tape machine.

Physical storage formats date faster than you think, but this is only a small and very obvious part of the problem. Consider the much more difficult job of finding software that can make sense of the data stored on the tape, even if you can read it.

When we store data electronically it’s not like putting paper in a filing cabinet which remains readable for thousands of years. It’s more like finding a filing cabinet filled with an ancient language and no sign of a Rosetta stone in sight.

Why is this such a problem? The answer is that until quite recently it was in companies' interests to keep the format used to store data a secret. The argument goes that if say Microsoft keeps the file format used by Word a secret then it means that you are locked into using the product and competitors can’t tempt you way by building something better and compatible. So you buy a copy of a word processor, use it to write lots of important documents and then the only way you can get at them is to use the very same word processor.

Meditate on this idea of just a few seconds and you are forced to realise that this is a crazy and completely unacceptable situation, yet we have mostly simply accepted it for many years. If you want to use an application then you buy the latest without much thought of the fact that its use of a proprietary file format locks you into using it in future. Considering the number of such file formats that have already passed into oblivion, along with products and companies, it is clear that this is a very real problem.

The good news is that in the past few years things have begun to change. With the increasing importance of open standards for storing data based on XML the entire marketing model seems to have done an about face. We have finally reached the point where sanity prevails and it is against a company’s best interests to keep a file format secret.

For example, Microsoft published the entire specification for its Office and related file formats. If you want to read all about the change in Microsoft’s attitude then have a look at their information on Interoperability. You can also check out the formats for the Office suite.

The fact that these extremely common formats are, at last, available for other application designers to use is welcome, but there is an even better solution to the problem. You can avoid using proprietary formats at all by adopting one of the XML-based standards. Sadly the word really is “standards” because at the moment there are two: Office Open XML (OOXML) and OpenDocument Format (ODF).

ODF was originally developed by Sun but is now an open ISO standard. Open in this context means that it can be freely used and implemented by anyone without fear of licensing or any other legal dispute. OOXML is Microsoft’s attempt to catch up, but it still isn’t a full standard and is causing some fuss about the methods being used to make it a standard.

Of course, irrespective of any other consideration, having two standards for the same thing isn’t good news. The slightly better news is that with the release of Office 2007 Service Pack 2 any day now Office will also work in ODF as well as OOXML.

Which one should you choose? In many ways which is unimportant. What is important is that you use an open standard – and remember to convert all of your existing documents into it.