It was reversible enough to write the Apache POI library. I maintain code that uses the HSSF streaming API portion of the library, which mainly gives you low-le

It was reversible enough to write the Apache POI library. I maintain code that uses the HSSF streaming API portion of the library, which mainly gives you low-level access to the structures in XLS files. The OO.org folks made some very nice documentation: http://www.openoffice.org/sc/excelfileformat.pdf http://www.openoffice.org/sc/excelfileformat.pdf