| .x | Lex Language Source Code |
| .x-png | Portable (Public) Network Graphic Bitmap |
| .x01 | Corel Paradox Secondary Index |
| .x02 | Corel Paradox Secondary Index |
| .x03 | Corel Paradox Secondary Index |
| .x04 | Corel Paradox Secondary Index |
| .x05 | Corel Paradox Secondary Index |
| .x06 | Corel Paradox Secondary Index |
| .x07 | Corel Paradox Secondary Index |
| .x08 | Corel Paradox Secondary Index |
| .x09 | Corel Paradox Secondary Index |
| .x1 | X1 Desktop Search Saved Search |
| .x10 | X Window Bitmap Dump |
| .x11 | X Window System Bitmap Image |
| .x13 | Hooligans Game Archive |
| .x20 | XTree Gold For Dos Help |
| .x32 | Adobe Xtra Format |
| .x3a | MOTIF XF |
| .x3d | X3D Format |
| .x3db | X3D Binary Format |
| .x3dv | Web3D X3D Graphics Image |
| .x3f | Sigma Camera RAW Picture Format |
| .x3g | MakerBot MakerWare Document |
| .x40 | XtreeGold Dos Help |
| .x4k | XML4King Configuration Format |
| .x50 | XtreeGold Dos Help |
| .x60 | XTree Gold For Dos Help |
| .x64 | Commodore 64 Emulator Disk Image |
| .x70 | XTree Gold For Dos Help |
| .x80 | Xtree Gold Dos Help |
| .x90 | XTree Gold For Dos Help |
| .xa | Sony PlayStation Audio/video Format |
| .xa0 | Xtree Gold Dos Help |
| .xab | Microsoft Outlook Express Address Book |
| .xac | SimCity Societies Game |
| .xad | EXotic ADlib Sound Format |
| .xadd | Expression Web Add-in |
| .xadml | Amiga Forever XADML |
| .xaf | Xml Compatible Animation Format |
| .xaiml | XAIML Database Format |
| .xaml | Windows Markup File |
| .xamlx | XAMLX Document Format |
| .xan | Worms 3D Map Format |
| .xap | Microsoft Silverlight Application Package Format |
| .xappl | Virtual Application Studio XML Application Configuration Format |
| .xar | Xara Vector Drawing Format |
| .xarc | The Longest Journey Audio |
| .xas | PTC Pro/Engineer Assembly Format |
| .xav | Final Draft AV Document |
| .xavc | Sony XAVC Video Format |
| .xb0 | Xtree Gold Dos Help |
| .xba | OpenOffice.org Basic Module Format |
| .xbap | Microsoft Silverlight Application Package |
| .xbb | DVIPDFMx Output |
| .xbc | SMART Notebook Format |
| .xbd | JAXB Schema |
| .xbdoc | Xiosis Scribe Document |
| .xbe | Xbox Executable Format |
| .xbel | XBEL Bookmarks Format |
| .xbf | Emperor Battle For Dune |
| .xbk | SMART Notebook Format |
| .xbl | Extensible Binding Language Format |
| .xblr | Output Raw XBRL |
| .xbm | X Windows System Bitmap Image |
| .xbmml | Braille Music Score |
| .xbmp | Area 51 Game |
| .xbn | Xnick Nick Backup |
| .xbplate | Xiosis Scribe Template |
| .xbrl | Extensible Business Reporting Language |
| .xbsav | Mass Effect 2 For Xbox Saved Game Format |
| .xbt | SMART Notebook Template Format |
| .xbx | Xbox Icon Or Picture |
| .xc0 | Xtree Gold Dos Help |
| .xc3 | Cast3D 3D Scene |
| .xcappdata | Apple Xcode Application Data Format |
| .xcarchive | Xcode Archive |
| .xcconfig | Apple Xcode Configuration Settings |
| .xcdatamodel | Xcode Core Data Model Format |
| .xcdatamodeld | Xcode Core Data Model Format |
| .xcel | Microsoft Excel For Mac Spreadsheet |
| .xcf | GIMP XCF Bitmap Image Format |
| .xch | LinkAssistant Project Settings |
| .xci | Adobe Reader Font Mapping |
| .xcl | XTree For Windows Script |
| .xcm | CmapTools Exported Concept Map |
| .xco | Xilinx CORE Generator Log |
| .xcode | Xcode Development Project Format |
| .xcodeplugin | Apple Xcode Extension |
| .xcodeproj | XCode Project Format |
| .xcof | Mac OS Object Library |
| .xcon | Conceal Encrypted Data |
| .xcorpus | Xaira Corpora |
| .xcp | XLNT Script Command |
| .xcplugin | Apple Xcode Extension |
| .xcplugindata | Xcode Plug-in Data |
| .xcr | Warlords Battlecry Game |
| .xcscheme | Apple Xcode Scheme |
| .xcsl | CineStyle Color Correction Settings Format |
| .xcsnapshots | Xcode Snapshot |
| .xct | XVI32 Conversion |
| .xctl | LabVIEW XControls |
| .xcu | OpenOffice.org Extension Control Format |
| .xcuserstate | Xcode |
| .xcworkspace | Xcode Workspace Format |
| .xd0 | XtreeGold Dos Help |
| .xda | Sencha Architect Project |
| .xdb | Norton AntiVirus Update Format |
| .xdc | Total Commander With DarkCrypt IV Plug-in Encrypted |
| .xdf | Externally Defined Function |
| .xdfl | XDFL Configuration |
| .xdi | WinArchiver Compressed ISO Image Format |
| .xdl | MS SQL Server XML Schema Format |
| .xdo | Oracle BI Publisher Resource Tracking |
| .xdoc | QuarkXPress 3.0 Document |
| .xdoclet | JBoss XDoclet Reference |
| .xdp | Acrobat XML Data Package Format |
| .xdr | XML Data Reduced Format |
| .xds | LCDStudio Design Format |
| .xdt | Win-Test Extra Data |
| .xdu | Backdoor.Win32.PcClient.xdu |
| .xdv | XeTeX |
| .xdw | DocuWorks Document Format |
| .xe0 | XtreeGold Dos Help |
| .xef | X-Genics EManager Form Data Format |
| .xej | Microsoft Expression Encoder Job Format |
| .xel | Microsoft Expression Encoder 3.0 Live Jobs Format |
| .xem | Sybase PowerDesigner Model Definition Format |
| .xen | Activision Guitar Hero 3 Data Format |
| .xensearch | XenCenter Saved Search Format |
| .xeo | Signwave Auto-Illustrator Extension |
| .xep | EManager File Packing Definition |
| .xeq | Sage MAS 90 Data |
| .xer | Primavera Project Management Propriety Exchange Format |
| .xes | X-Genics EManager Skins Definition |
| .xesc | Microsoft Expression Encoder Screen Capture Format |
| .xet | X-Genics EManager Process Definition |
| .xev | X-Genics EManager Auto-update Format |
| .xevgenxml | Adobe Dreamweaver |
| .xex | Xbox 360 Executable Format |
| .xez | X-Genics EManager Template Package |
| .xfa | OneCncXR CAD |
| .xfbin | Naruto Shippuden: Ultimate Ninja Storm 2 |
| .xfc | X-Fonter Font Collection |
| .xfd | Adobe XFDL Format XML Form Format |
| .xfdf | Adobe Acrobat Forms Document |
| .xfdl | XFDL Format |
| .xff | XFRX Database Output |
| .xfi | XICE Desktop Encrypted |
| .xfl | Adobe Flash Exchange Format |
| .xfm | OmniForm XML |
| .xfn | Corel Ventura Printer Font |
| .xfo | XSL-FO Formatted Form |
| .xfp | Microsoft SharePoint Extending Form Library Properties |
| .xfr | Ventura Publisher Bitmap Editor Font Format |
| .xfs | Gunbound Format |
| .xft | Adobe Form Designer Form |
| .xfz | French FlashCards Vocabulary |
| .xg0 | Corel Paradox Secondary Index |
| .xg1 | Corel Paradox Secondary Index |
| .xg2 | Corel Paradox Secondary Index |
| .xg3 | Corel Paradox Secondary Index |
| .xg4 | Corel Paradox Secondary Index |
| .xg5 | Corel Paradox Secondary Index |
| .xga | Diamond Mind Baseball Game Account Information |
| .xgd | Xbox 360 Game Disc Layout |
| .xgl | XGL 3D CAD Model |
| .xgll | EASE SpeakerLab Text |
| .xgml | Graph Modeling Language XML Format |
| .xgmml | XGMML Graph Format |
| .xgo | GeoConcept Add-on |
| .xgp | Xfire Profile Patcher Game List Format |
| .xgs | Disk Image Format |
| .xhb | HomeBank Data |
| .xhp | OpenOffice.org Extension Help Format |
| .xht | Extensible HyperText Markup Language Format |
| .xhtm | Extensible HTML Format |
| .xhtml | Extensible HTML Format |
| .xi | Fastracker 2.0 Instrument Format |
| .xib | Apple Interface Builder Format |
| .xif | ScanSoft Pagis Format |
| .xig | XML Instance Generator |
| .xil | Xilize |
| .xilinc | Xilize Defintion |
| .xilize | Xilize Configuration |
| .xim | X11 Xim Toolkit Bitmap |
| .xin | OmniMark Include |
| .xip | Xbox Dashboard |
| .xise | Xilinx ISE Project Format |
| .xiso | Xbox ISO |
| .xit | SpatialAnalyzer |
| .xit64 | SpatialAnalyzer |
| .xix | IIS NNTP Subject Lists |
| .xiz | Ximinez |
| .xjb | OEPE JAXB Wizard Bindings |
| .xjt | Compressed GIMP Image |
| .xkm | X KeyBoard |
| .xl | Microsoft Excel Spreadsheet Format |
| .xla | Microsoft Excel Add-in Format |
| .xla5 | Microsoft Excel 5 For Mac Add-in |
| .xla8 | Microsoft Excel 98 For Mac Add-in |
| .xlam | Microsoft Excel 2007/2010 Open XML Macro-enabled Add-in Format |
| .xlamenx | Egis Encrypted Excel XLAM |
| .xla_ | Microsoft Excel 4 For Mac Add-in |
| .xlb | Microsoft Excel Toolbars Format |
| .xlb4 | Microsoft Excel 4 For Mac Toolbars |
| .xlb5 | Microsoft Excel 5 For Mac Toolbars |
| .xlb8 | Microsoft Excel 98 For Mac Toolbars |
| .xlbn | Microsoft Excel 1 For Mac Toolbars |
| .xlc | Microsoft Excel Chart Format |
| .xlc3 | Microsoft Excel 3 For Mac Chart |
| .xlc4 | Microsoft Excel 4 For Mac Chart |
| .xlc_ | Microsoft Excel 2 For Mac Chart |
| .xld | Microsoft Excel Dialogue Format |
| .xldb | AQUA Data |
| .xlf | XLIFF Document Format |
| .xlg | AutoCAD External Reference Log |
| .xlgc | ExpressK Database Format |
| .xli | SIEMENS PLM Software NX 7.5 Log |
| .xliff | XLIFF Localization Format |
| .xlk | Microsoft Excel Backup Format |
| .xll | Microsoft Excel Add-in Format |
| .xll_ | Microsoft Excel 4 For Mac Add-in |
| .xlm | Microsoft Excel Macro Format |
| .xlm3 | Microsoft Excel 3 For Mac Macro |
| .xlm4 | Microsoft Excel 4 For Mac Macro |
| .xlmv | Thunder Mall Video Format |
| .xlmx | Microsoft Excel Macro-enabled Spreadsheet |
| .xlm_ | Microsoft Excel 2 For Mac Macro |
| .xlnk | XML Link Format |
| .xlo | Autodesk Inventor Export Journal |
| .xlpf | Microsoft Excel For Mac Setting |
| .xlr | Microsoft Works Spreadsheet Or Chart Format |
| .xls | Microsoft Excel 97 To 2003 Workbook Format |
| .xls3 | Microsoft Excel 3 For Mac Spreadsheet |
| .xls4 | Microsoft Excel 4 For Mac Spreadsheet |
| .xls5 | Microsoft Excel 5 For Mac Spreadsheet |
| .xls8 | Microsoft Excel 98 For Mac Spreadsheet |
| .xlsb | Microsoft Excel 2007/2010 Binary Workbook Format |
| .xlsenx | Egis Encrypted Excel XLS |
| .xlshtml | Microsoft Office Excel HTML Document Format |
| .xlsm | Microsoft Excel 2007/2010 Open XML Macro-enabled Workbook Format |
| .xlsmhtml | Microsoft Excel MIME HTML Spreadsheet Format |
| .xlsx | Microsoft Excel 2007, Excel 2010 And Excel 2013 Open XML Workbook Format |
| .xlsxenx | Egis Encrypted Excel XLSX |
| .xls_ | Microsoft Excel For Mac Spreadsheet |
| .xlt | Microsoft Excel 97 To 2003 Workbook Template Format |
| .xlthtml | Microsoft Office Excel HTML Template Format |
| .xltm | Microsoft Excel 2007/2010 Open XML Macro-enabled Workbook Template Format |
| .xltx | Microsoft Excel 2007/2010 Open XML Workbook Template Format |
| .xlv | Microsoft Excel VBA Module Format |
| .xlw | Microsoft Excel Workspace Format |
| .xlw3 | Microsoft Excel 3 For Mac Workbook |
| .xlw4 | Microsoft Excel 4 For Mac Workbook |
| .xlw5 | Microsoft Excel 5 For Mac Workbook |
| .xlw_ | Microsoft Excel 2 For Mac Workbook |
| .xlxml | Microsoft Excel XML Worksheet |
| .xlz | Crossword Power Tools Crossword Library |
| .xm | FastTracker 2 Instrument |
| .xmap | XMind 2007/2008 Workbook |
| .xmb | Lucas Arts X-Wing Mission Briefing Format |
| .xmc | Lingoes Configuration |
| .xmcd | PTC Mathcad Worksheet Format |
| .xmcdz | PTC Mathcad Compressed Worksheet Format |
| .xmct | Mathcad Template Format |
| .xmd | GameJack Virtual CD Or DVD Image Format |
| .xme | GME |
| .xmef | TextMap Evidence Format |
| .xmf | CDRWin Virtual CD Image Format |
| .xmg | The Longest Journey XMG |
| .xmi | Miles Sound System Extended MIDI Files |
| .xmind | XMind Workbook Format |
| .xmit | IBM XMIT Data |
| .xml | XML Document Format |
| .xml-prev | VirtualBox XML Settings Backup |
| .xmla | XML For Analysis Source |
| .xmljet | Eclipse JET XML Template |
| .xmlper | LeCroy Binary Waveform Format |
| .xmls | Microsoft Excel 2003 XML |
| .xmlx | Excel Spreadsheet |
| .xmm | 3ds Max XML Animation Map Format |
| .xmmap | MindManager XML Map Format |
| .xmmas | MindManager XML Theme |
| .xmmat | MindManager XML Template |
| .xmo | Adobe Authorware Movie Driver |
| .xmod | Datawatch Monarch Model |
| .xmp | Adobe Extensible Metadata Platform Format |
| .xmpses | Adobe Premiere Elements |
| .xmpskin | XMPlay Skin |
| .xmpz | Miradi XML Project Format |
| .xms | Microsoft EXtended Memory Specification |
| .xmt | XMind Workbook Template |
| .xmta | Microsoft Visual Studio XMTA Document |
| .xmv | Microsoft Xbox Video Format |
| .xmx | AutoCAD External Message Compiled |
| .xmz | Fasttracker 2 Extended Module Format |
| .xn | Cygnus Ld-scripts |
| .xnb | XNA Game Studio Express XNA Framework Content Pipeline Binary Format |
| .xnd | ExNode Download |
| .xnf | Extensible Numerical |
| .xnk | Microsoft Exchange Shortcut Format |
| .xnode | LabVIEW |
| .xnp | XnView Addon |
| .xnt | QuarkXPress Extension Format |
| .xnv | NVision Layout |
| .xob | EasyBuilder 8000 Compiled Code |
| .xof | RenderMorphics Reality Lab 3D Image Format |
| .xojo_binary_menu | Xojo Binary Menu |
| .xojo_binary_project | Xojo Binary Project |
| .xojo_binary_window | Xojo Binary Window |
| .xojo_menu | Xojo Menu |
| .xojo_project | Xojo Programming Project |
| .xojo_window | Xojo Window |
| .xojo_xml_menu | Xojo XML Menu |
| .xojo_xml_window | Xojo XML Window |
| .xol | Swiss Map Overlay Format |
| .xom | Worms 3D Object Format |
| .xoml | Windows Workflow Format |
| .xop | IGOR Pro Add-on |
| .xov | RapidForm XOV 3D Inspection/Model |
| .xp | WindowBlinds Temporary Format |
| .xp0 | SecretPhotos Puzzle Graphic Image |
| .xp2 | XPilot NG |
| .xp3 | KiriKiri Package Format |
| .xp4 | KiriKiri Package |
| .xpac | Sonic & Sega All-Stars Racing For PC Game Audio Archive |
| .xpaddercontroller | Xpadder Controller Layout Format |
| .xpadderprofile | Xpadder Settings |
| .xpb | XPB! Basic Source Code |
| .xpd | XML Pipeline Document Format |
| .xpdl | XPDL Module |
| .xpf | XProtector Project |
| .xpg | Autoplay Media Studio Exported Page |
| .xpgt | EPUB XML Stylesheet Page Template |
| .xpi | Firefox Browser Extension Format |
| .xpj | Micro Planner X-Pert Project Format |
| .xpk | PSpice Library Format |
| .xpku | Apple Mac OS X Universal Binary Package |
| .xpl | X-Plane Plug-in Format |
| .xpl2 | TerraExplorerPro LOD Parameter |
| .xpm | X11 Pixmap Graphic |
| .xpng | Portable (Public) Network Graphic Bitmap |
| .xpp | X++ Source Code Format |
| .xpr | PTC Pro/ENGINEER Part Format |
| .xpr3 | QuarkXpress 3.0 Mac |
| .xprj | Monarch XML Project |
| .xps | XML Paper Specification Format |
| .xps~ | WindowBlinds Temporary |
| .xpt | Mozilla Firefox Component |
| .xptin | Xpswmm Hydrology Data |
| .xpw | Accessible FormNet Fillable Form |
| .xpx | Intercon FormNet |
| .xpy | MarketBrowser |
| .xp~ | WindowBlinds Temporary |
| .xq | XQuery Format |
| .xql | XML Query Language Format |
| .xqm | XQuery Module |
| .xqt | SuperCalc Macro Spreadsheet Format |
| .xquery | XQuery Source Code Format |
| .xqy | XQuery Source Format |
| .xr | Cygnus Ld-scripts |
| .xrc | WxWidgets WxPython Resource |
| .xrd | Core Wars Data |
| .xrdml | PANalytical XRD Measurement Data XML |
| .xref | IBM AIX Cross Reference |
| .xrf | WordSearch Cross Reference Format |
| .xrff | Extensible Attribute-Relation File Format |
| .xrl | PowerDesigner Report |
| .xrm-ms | Microsoft Security Certificate |
| .xrns | Extended Renoise Song Format |
| .xrp | RationalPlan Format |
| .xrs | Dig It! Game |
| .xrx | Expression Encoder Media Profile Settings |
| .xry | XRY Data Format |
| .xs | Age Of Empires 3 Map AI Generator Format |
| .xs4 | XESS Worksheet |
| .xs5 | XESS Worksheet |
| .xsb | XACT Sound Bank |
| .xsc | Microsoft Visual Studio XSC Format |
| .xsd | XML Schema Description Format |
| .xsf | Microsoft Office InfoPath Format |
| .xsi | SOFTIMAGE|XSI 3D Model |
| .xsiaddon | SOFTIMAGE XSI Add-on Format |
| .xsl | XML Stylesheet Format |
| .xslic | XenServer License Format |
| .xslt | XSL Transform Format |
| .xsm | SimCity Societies Game |
| .xsn | Microsoft Office InfoPath Template Form Format |
| .xso | Expresso Project |
| .xsp | XBMC Smart Playlist Format |
| .xspf | XML Shareable Playlist Format |
| .xsql | Oracle XSQL Servlet Server Side |
| .xsr | FabTrol MRP |
| .xss | XML Stylesheet Format |
| .xsslog | Microsoft SharePoint WorkSpace Groove Log |
| .xssr | Microsoft SharePoint WorkSpace Groove |
| .xst | Microsoft Outlook Personal Folders Format |
| .xstb | TextBridge |
| .xstk | XStarter Task |
| .xsu | Fortran 77 Library |
| .xsvf | Xilinx Serial Vector Format |
| .xsx | Microsoft Visual Studio XML Schema Layout Format |
| .xt | FastTracker Music Track Format |
| .xtc | XTrkCAD Project |
| .xtd | XML Type Definition |
| .xterme | Winstep Extreme Theme |
| .xtf | EXtended Triton Format |
| .xtg | QuarkXpress Tags Format |
| .xtic | ActivInspire Ticker |
| .xtl | Vietcong Game Data Format |
| .xtm | CmapTools Exported Topic Map Format |
| .xtml | XML4web Virtual HTML Document |
| .xtmp | Avid Xpress Pro Template |
| .xtnd | Adobe Acrobat For Mac Plug-In |
| .xtodvd | ConvertXtoDVD Project |
| .xtp | XTreeGold Overlay |
| .xtra | Adobe Director Xtra |
| .xtreme | Winstep Xtreme Theme Pack Format |
| .xtrl | XTND Translator |
| .xtxt | Xtext |
| .xui | Xbox 360 Skin Format |
| .xul | Firefox XML User Interface Language Format |
| .xur | Xbox 360 Compiled Skin Format |
| .xv | Khoros Visualization Bitmap Image |
| .xv0 | Lattice XVL Structure Format |
| .xv2 | V-XVL Geometry |
| .xv3 | P-XVL Geometry Format |
| .xva | Citrix Xen Virtual Appliance Format |
| .xvct | VISE XML Project Format |
| .xvg | Grace Document |
| .xvid | XviD Codec |
| .xvl | EXtensible Virtual World Description Language Document |
| .xvm | VMware Console Configuration Format |
| .xvmconf | World Of Tanks Configuration Format |
| .xvo | RatDVD Internal |
| .xvu | BOClean Database Format |
| .xwb | XACT Wave Bank Format |
| .xwc | Starbreeze Sound |
| .xwd | X Window Window Screen Dump Or Bitmap |
| .xwf | OmniPage Workflow Format |
| .xwi | Star Wars: X-Wing Mission |
| .xwk | Crosstalk Keyboard Mapping Format |
| .xwm | The Elder Scrolls V: Skyrim Music |
| .xwma | XWMA Audio Compression Format |
| .xwmv | Microsoft Windows Media |
| .xwp | Xerox Writer Document |
| .xws | Xara Webstyle Format |
| .xx | XXEncoded Format |
| .xxd | Brixx Planner Calendar Format |
| .xxe | XXEncoded Format |
| .xxx | Compucon/Singer PSW Embroidery Design Format |
| .xy | XyWrite Document |
| .xy3 | XYWrite III Document |
| .xyp | XY Write III Plus Document |
| .xys | XYplorer Script Format |
| .xyw | XYWrite For Windows 3x/4.0 Document |
| .xyz | Molecule Specification Format |
| .xyze | Radiance Map |
| .xyzi | 3rdTech Scanner |
| .xyzrgb | 3rdTech XYZ RGB Graphic |
| .xyzv | Celestia Sampled Trajectory Format |
| .xz | XZ Utils Compressed Archive |
| .xzfx | ZipLogix ZipForm Format |
| .xzm | Slackware Linux Package |
| .x_b | Parasolid Document Format |
| .x_t | Parasolid File Format |
File extensions are not normally displayed to users. To change this, go to Control Panel, select Appearance and Personalization and Folder Options. Next, select the View and find the option "Hide extensions for known file types". The option should be deselected (cleared) and confirmed with OK.
