Teach DiffDog a New Trick You can easily train DiffDog, Altova’s diff/merge tool for files, directories, and databases, to correctly interpret new file types. For instance, more and more file standards are taking advantage of the Zip compression format to deliver entire sets of files in a single convenient package. Let’s say you want to use DiffDog to examine and compare files created by Google Earth that are saved in .kmz archives. When you initially open a folder containing .kmz documents, then attempt to compare two files in a DiffDog document window, DiffDog reports the .kmz files contain binary content: All you have to do is add the .kmz file extension in the File Types tab of the DiffDog Options dialog: And click the Zip conformant radio button to assign the correct behavior: Now that DiffDog understands the .kmz file extension is a Zip archive, it expands the Directory compare window to list all the component files. You can see differences inside the archives. When you double-click any file pair, DiffDog automatically fetches them from the Zip archives and presents them for interactive editing in a new File Compare window. However, some of the file types enclosed in the Zip archive are also unknown. We learned from reading the XML Aficionado blog entry on Google Earth and XMLSpy that .kml files are an open XML-based standard for geo-spatial information. We can add .kml to DiffDog files types and specify XML-conformant syntax coloring: Now DiffDog displays the files with syntax coloring and we can apply all the DiffDog XML-aware differencing functionality. If you dig deeper into the .kmz archive, you’ll discover .dae files are also XML-based. After you add .dae to the DiffDog files list and set it as XML-compliant, give yourself a treat! DiffDog is available as a standalone tool or as part of the Altova MissionKit tool suite. The recently released DiffDog Version 2009 added powerful database content diff/merge capabilities – take a free trial for a walk around the block.