Since that time, Microsoft had opened the documentation on all office file formats, and it's really good - very detailed. The documentation support team is very

Since that time, Microsoft had opened the documentation on all office file formats, and it's really good - very detailed. The documentation support team is very responsive when something isn't clear. Plus they provide quite many additional tools for work with binary files, and to validate them if you're implementing generation of these files. But the formats themselves sometimes quite unlogical, especially when you embed one into another. And binary formats are very different for every office components. For example, PowerPoint - contains most of information in one big blob inside OLE, while Excel and Word tend to store smaller objects separately. P.S. I've implemented data extraction for all MS office files for commercial products, and also participated in development of catdoc program about 10 years ago