Software & Apps File Types What Is an XTM File? How to open, edit, and convert XTM files By Tim Fisher General Manager, VP, Lifewire.com Tim Fisher has 30+ years' professional technology support experience. He writes troubleshooting content and is the General Manager of Lifewire. our editorial process Facebook Twitter LinkedIn Tim Fisher Updated March 18, 2020 File Types Design Cryptocurrency MS Office Windows Linux Google Drive Apps File Types Backup & Utilities View More Tweet Share Email A file with the XTM file extension is most likely a CmapTools Exported Topic Map file. These files use the XML format to store graphics and text for use in the IHMC CmapTools (concept map tools) software. The Xtremsplit Data file format uses the XTM file extension as well. They're used with the Xtremsplit software to split a large file into smaller pieces, and also to join said pieces back together, so that they're easier to send online. How to Open an XTM File CmapTools Exported Topic Map XTM files can be opened on Windows, macOS, and Linux with the IHMC CmapTools software. This program is used to express concepts in a graphical flowchart form. The CmapTools Documentation & Support page is a great resource for learning how to use the CmapTools program. There are forums, FAQs, help files, and videos. Since XTM files are based on the XML file format, any program that opens XML files can also open XTM files. However, the purpose of the CmapTools software is to create a visual representation of the text, annotations, graphics, etc., that's easy to read and follow in sequence, so viewing the data in an XML or text file viewer like a text editor, isn't nearly as beneficial as using CmapTools. Some XTM files are saved in a way that lets recipients view the Cmap with any web browser so that they don't need to have CmapTools installed. When this is done, the Cmap is saved in an archive format like ZIP, TAR, or something similar. To open this file, the recipients just need a standard file extractor tool like the free 7-Zip. Xtremsplit Data files are named something like file.001.xtm, file.002.xtm, and so on, to designate the different pieces of the archive. You can open these XTM files using the portable software Xtremsplit. It's possible that a file zip/unzip like 7-Zip, or the free PeaZip can be used to join these XTM files as well. The Xtremsplit program is in French by default. You can change it to English if you select the Options button and change the Langue option from Francais to Anglais. How to Convert an XTM File In CmapTools, use the File > Export Cmap As menu to convert the XTM file to an image file like BMP, PNG, or JPG, as well as to PDF, PS, EPS, SVG, IVML, HTML, or CXL. A file that has been split into XTM files definitely can't be converted to any other format until it has been rejoined using Xtremsplit. For example, an 800 MB MP4 video file is unable to be converted to any other video format until the pieces of it are joined back together into the original MP4 format. As for converting the XTM files themselves, you simply can't do it. Remember, these are pieces of a larger whole that need to be joined together for any practical use. The individual XTM files that make up a file (like the MP4) are of no use apart from the other pieces. Still Can't Open the File? If none of the above suggestions work to open your file, there's a good chance you're not really dealing with an XTM file. Some files use a file extension that looks an awful lot like XTM even though the formats have nothing to do with each other. For example, XMI files share two of the same letters as the XTM file extension but they could be Extended MIDI files that have nothing to do with the other formats mentioned on this page. TMX is similar. That file extension belongs to the Translation Memory Exchange file format and requires a different program to open the file.