[gregopet]

Microsoft really doesn't want anyone to reliably copy their formats. Their standard is purposefully complicated and convoluted, it was almost rejected by ISO for this reason and it took heavy lobbying before it passed (I know of this personally as the ISO vote went through national ISO bodies).

I've worked with the Java implementation for writing Office files, the Apache POI. The internal package names for these classes are "hssf", "hwpf" and so on. It's not very obvious why until you Google it and, well, "hwpf" stands for "horrible word processor format", "hssf" is "horrible spreadsheet format" and so on. Implementing these things is often difficult for good reason, and sometimes for not so good reasons, but this is the first time I've encountered developers expressing such direct hostility towards what they were trying to implement.