Microsoft Office Binary (doc, xls, ppt) File Formats
Now isn't this interesting. The Microsoft Office Binary (doc, xls, ppt) File Formats specifications are available for download. Although I suspect the Office 2007 XML based files would be much easier to work with.
Will the MDB/ACCDB format ever be published? All kinds of interesting speculation there but I have no idea
Note that there is a group working on reverse engineering the MDB format. MDB Tools is a set of open source libraries and utilities to facilitate exporting data from MS Access databases (mdb files) without using the Microsoft DLLs. Thus non Windows OSs can read the data. Or, to put it another way, they are reverse engineering the layout of the MDB file. Download the file and look at the hacking file.
What is annoying to me are the Access data recovery outfits which have copied that hacking file onto their web site with attributing the original creators of that document. See http://www.fdrlab.com/files/accessfileformat.txt and http://www.e-tech.ca/001-AccessFileFormat.asp. This web site copied part of it http://www.filerepair.net/bb/viewtopic.php?p=3&sid=096e617bca1533e1bdf7849e4fc70a69 but then referenced another web site http://www.etechrecovery.com/001-AccessFileFormat.asp.