Hi, the code in the overview2 branch is nearly ready for trunk now, but the configuration and documentaion is not yet ready. The current implementation in the overview2 branch adds these new options: --overview-levels like levels, specifies additional levels that are to be written to the overview map. --remove-ovm-work-files If overview-levels is used, mkgmap creates one additional file with the prefix ovm_ for each map (*.img) file. These files are used to create the overview map. With option --remove-ovm-work-files=true the files are removed after the overview map was created. The default is to keep the files. The overview map is created by default (like the *.tdb file) if any input file is processed. It is empty if you don't use overview-levels (like in the trunk version) I noticed a rather confusing behaviour (also in the trunk): the option --tdbfile is not needed to create the *.tdb file, but it has an influence on the creation of the index files: if (indexOpt && (tdbOpt || !gmapOpt)) { addCombiner(new MdrBuilder()); addCombiner(new MdxBuilder()); } This also means that even with --no-tdbfile the tdb file and the overview map is produced. I think we should completely remove the tdbfile option and assume it to be true in the above code snippet. Gerd