MSOfficeXML: Does long-term viability matter?
Brian Jones's recent post Does tag size matter? points out the contradictions inherent in Microsoft's efforts to push the use of its new MSOfficeXML file formats.
Well, uh, then why did you change the file format? Wouldn't the binary file format be even faster?
I don't think it is for the benefit of developers. The raw complexity of the MSOfficeXML spec means that no high-level programmer is going to interact with a file without using a library. Thus, the fact that it is XML doesn't really matter that much, as long as they have a library that knows how to handle it. And since the binary format still exists, they'll still need a utility or function to convert back and forth between binary and XML flavors.
My guess is because a lot of users do care.
"Premature optimization is the root of all evil (or at least most of it) in programming." Donald Knuth
If your design goal is fast load times and 100% backwards compatibility with every quirk that ever existed (no "feature" loss in his terms), then maybe having smaller tags and a 4,000 page spec is a good thing.
If your design goal is long-term preservation and access to the data, then maybe longer but meaningful tags make sense.
File Formats: MSOfficeXML