| wsd | WordStar 2000 Document |
| wsdl | Web Services Description Language Document |
| wsq | WinEsquema Flowchart Document |
| wss | Cast Soft wysiwyg Spreadsheet |
| wss | Worksheet Builder Self-Contained Worksheet |
| wst | WordStar 2000 Template |
| wst | Worksheet Builder Worksheet Template |
| wswriter | TechWriter for Web Services Document |
| wt0 | WordExpress Document Template |
| wt4 | Lotus 1-2-3 Smartmaster Template |
| wvl | WorkView3D Links |
| wvw | Interleaf WorldView Document |
| wws | Writing With Symbols Document |
| wwt | Microsoft Works Template |
| wxmx | wxMaxima Document |
| wxp | EXP Document |
| wxs | Easy Cross stitch design |
| wyn | WYNN Document |
| wyx | WYNN Document |
| wzfolder | WhizFolders Document |
| wzn | WhizFolders Note Document |
| x3d | X3D Scene |
| x3db | X3D Binary Scene |
| x3dbz | Compressed X3D Binary Scene |
| x3dv | X3D Classic VRML |
| x3dvz | Compressed X3D Classic VRML |
| x3dz | Compressed X3D Scene |
| x3g | MakerBot X3G Document |
| xav | Final Draft AV v2 Document |
| xbc | SMART Notebook Document |
| xbd | Xerox DocuWorks Binder Document |
| xbdoc | Xiosis Scribe Document |
| xbel | XBEL Bookmark |
| xbk | SMART Notebook Document |
| xbmml | BMML File with Metadata |
| xbplate | Xiosis Scribe Template |
| xbrl | eXtensible Business Reporting Language |
| xbt | SMART Notebook Template |
| xcm | Concept Map |
| xddm | OpenVSP v2 VSP Design Document |
| xdes | OpenVSP VSP Design Document |
| xdoc | QuarkXPress 3.0 Document |
| xdp | XML Data Package |
| xdr | XML-Data Reduced Schema |
| xdv | XeTeX Extended DVI Document |
| xdw | Xerox DocuWorks Document |
| xfa | XML Forms Architecture Document |
| xfd | XFDL Document |
| xfdf | Adobe Acrobat XFDF Document |
| xfo | XSL-FO Formatted Form |
| xfp | Microsoft InfoPath Property Promotion |
| xgl | XGL 3D CAD Model |
| xgml | Graph Modeling Language XML |
| xgz | MegaBitz XGL Vector Drawing |
| xhf | XHeader Document |
| xht | XHTML Document |
| xig | XML Instance Generator Document |
| xla | Microsoft Excel VBA Add-in |
| xla8 | Microsoft Excel 98 for Mac Add-in |
| xlam | Microsoft Excel 2007 VBA Add-in |
| xlb | Microsoft Excel toolbar Setup |
| xlc | Microsoft Excel Chart File |
| xlc3 | Microsoft Excel 3 for Mac Chart Document |
| xlc4 | Microsoft Excel 4 for Mac Chart Document |
| xlcsv | Microsoft Excel Comma-Separated Values Document |
| xld | Microsoft Excel Dialogue |
| xlf | XLIFF Document |
| xline | XLine Mind Map Document |
| xlk | Microsoft Excel XLS Backup |
| xll | Microsoft Excel Add-in |
| xlm | Microsoft Excel Macro Definition |
| xlm4 | Microsoft Excel 4 for Mac Macro Data |
| xlr | Microsoft Works Spreadsheet |
| xls | Microsoft Excel Worksheet |
| xls3 | Microsoft Excel 3 for Mac Document |
| xls4 | Microsoft Excel 4 for Mac Document |
| xls5 | Microsoft Excel 5 for Mac Document |
| xls8 | Microsoft Excel 98 for Mac Document |
| xlsb | Microsoft Excel 2007 Document |
| xlse | Document Manager Encrypted XLS Document |
| xlshtml | Microsoft Excel HTML Spreadsheet |
| xlsl | Document Manager Locked Excel Document |
| xlsm | Microsoft Excel 2007 Document |
| xlst | OnlyOffice Internal XLSX Document |
| xlsx | Microsoft Excel 2007 Document |
| xlsxe | Document Manager Encrypted XLSX Document |
| xlsxl | Document Manager Locked XLSX Document |
| xlt | Microsoft Excel Template |
| xlthtml | Microsoft Excel HTML Spreadsheet Template |
| xltm | Microsoft Excel 2007 Template with Macros |
| xltx | Microsoft Excel 2007 Template |
| xlv | Microsoft Excel VBA Module |
| xlw | Microsoft Excel Workbook Document |
| xlw3 | Microsoft Excel 3 for Mac Workbook Document |
| xlw4 | Microsoft Excel 4 for Mac Workbook Document |
| xlw5 | Microsoft Excel 5 for Mac Workbook Document |
| xlxml | Microsoft Excel XML Worksheet |
| xlz | Open Language Tools XLIFF Archive |
| xmap | XMind 2007/2008 Workbook |
| xmcd | Mathcad Worksheet Document |
| xmcdz | Mathcad Compressed Worksheet |
| xmct | Mathcad XML Worksheet Template |
| xmind | XMind Workbook |
| xml | Extensible Markup Language File |
| xmls | Microsoft Excel 2003 XML Document |
| xmp | XMind Markers Package |
| xmt | Romulus 3D Modeler Data |
| xmt | XMind Template |
| xod | Silverlight XPS Document |
| xoi | eZediaMX Locked Presentation Document |
| xopp | Xournal++ Notebook |
| xov | Rapidform XOV 3D Model |
| xpdl | XML Process Definition Language Document |
| xpf | Homestead Sitebuilder Document |
| xpf | X-Stitch Studio Design |
| xpr3 | QuarkXPress for Mac Document |
| xps | NetSim Lab Documentation Data |
| xps | XML Paper Document |
| xpwe | PriMus XML Exchange Document |
| xrw | Architag XRay XML Editor Document |
| xs3 | XESS Worksheet |
| xsc | Transcribe! Transcription Document |
| xscscpt | Transcribe! Script |
| xsd | Microsoft InfoPath XML Schema |
| xsd | Pattern Maker Design |
| xsf | Microsoft InfoPath Form Definition |
| xsh | Xshade 3D Model |
| xslt | Extensible Stylesheet Language Transformations |
| xsn | Microsoft InfoPath Form Template |
| xsp | Cross Stitch Pro Design |
| xss | Ability Office Spreadsheet |
| xss | Cross Stitch Pro Read-only Design |
| xsslog | Microsoft SharePoint WorkSpace Groove Log Data |
| xssr | Microsoft SharePoint Workspace Data |
| xswriter | TechWriter for XML Schemas Document |
| xsx | Microsoft XML Schema Designer View |
| xtg | QuarkXPress Tags File |
| xtp | xTime Project Document |
| xtps | xTeam Document |
| xtrn | Call Report Pro XBRL Instance Document |
| xvi | XTherion Vector Image |
| xvl | Extensible Virtual World Description Language Document |
| xwf | OmniPage Workflow |
| xwp | Xerox Writer Text Document |
| xxn | Dimenzo Text Editor Document |
| xy | XyWrite Document |
| xy3 | XyWrite III Document |
| xy4 | XyWrite IV Document |
| xyd | XYPad Drawing Document |
| xyp | XyWrite III Plus Document |
| xzfx | ZipLogix ZipForm Transaction |
| xzip | Hungarian Tendering System Document |
| yak | KayakFoundry 3D Design Documen |
| yar | StarBoard Document |
| yar | Yar Scene |
| ybak | MindGenius v1 Document Backup |
| ybk | Microsoft Encarta Yearbook |
| ydb | Yutori 7 Document |
| ydd | YANG Designer Document |
| ydl | SGI PowerFlip YAODL 3D Image |
| ydo | Yarston Text Editor Document |
| yes | Quick Bible Document |
| ygf | Y Graph Format |
| yka | Yenka Model |
| ymap | MindGenius v1 Document |
| z3d | ZModeler 3D Model |
| z3n | ZW3D Neutral Format File |
| zabw | AbiWord Gzip Compressed Document |
| zad | ZadGen Document |
| zax | Z-Axis 3D Office Design Document |
| zbr | ZBrush Document |
| zcl | Zoner Callisto Clipart Document |
| zcn | OmniPage Language Data |
| zdb | Avery DesignPro Design |
| zdg | ZiffNet ZView Compressed Document |
| zdl | Avery DesignPro Label |
| zdx | Avery DesignPro Clipart Index |
| zed | Compressed GEDCOM Document |
| zed | ZX-Edit Document Block |
| zgl | Compressed XGL Document |
| zgt | Oren-made Scientific Document |
| zhp | Compressed Swiftview Document |
| zhtml | Secure IE Zipped HTML |
| zir | C.a.R. Figure |
| zjs | Zenographics ZjStream SuperPrint Zj Stream |
| zmp | Zoner Callisto Print Layout |
| zno | Zinio Reader Magazine |
| zoi | eZediaMX Unlocked Presentation Document |
| zpl | Zebra Programming Language Document |
| zpweb | Zeta Producer Web Document |
| zrtf | Nisus Writer Pro Compressed RTF Document |
| zrz | jHIS Invoice Template |
| zsw | School Writing Document |
| ztf | DVD Label Template |
| ztx | C.a.R. Exported Image |
| zvw | Z-Axis 3D Viewer Document |
| zw | Chinese Text File |
| zwl | WinLabel v3 Document |
| zxml | Cubetto 5.0 Compressed XML Document |