File extension	The full name of the file	Popularity
File extension X	DirectX Model File
File extension X32	Adobe Xtra File
File extension X3D	Xara3D Project
File extension X3F	SIGMA X3F Camera RAW File
File extension X4K	XML4King Configuration File
File extension X64	Commodore 64 Disk Image
File extension XA	The Sims Audio File
File extension XADD	Expression Web Add-in
File extension XAF	3ds Max XML Animation File
File extension XAIML	XAIML Chatterbot Database File
File extension XAML	Windows Markup File
File extension XAMLX	XAMLX document file
File extension XAN	Worms Map File
File extension XAP	Silverlight Application Package
File extension XAPPL	Spoon XML Application Configuration File
File extension XAR	Xara Xtreme Drawing
File extension XAS	Pro/ENGINEER Assembly Instance Accelerator File
File extension XBA	OpenOffice.org Basic Module File
File extension XBAP	Microsoft Silverlight application package
File extension XBC	SMART Notebook File
File extension XBDOC	Xiosis Scribe Document
File extension XBE	Xbox Executable File
File extension XBEL	XBEL Bookmarks File
File extension XBK	XenServer Backup File
File extension XBL	Extensible Binding Language File
File extension XBM	X11 Bitmap Graphic
File extension XBPLATE	Xiosis Scribe Template
File extension XBSAV	Mass Effect 2 Xbox Saved Game
File extension XBT	SMART Notebook Template File
File extension XCAPPDATA	Xcode App Data File
File extension XCARCHIVE	Xcode Archive
File extension XCDATAMODEL	Xcode Core Data Model File
File extension XCDATAMODELD	Xcode Core Data Model File
File extension XCF	GIMP Image File
File extension XCODE	Xcode Project
File extension XCODEPROJ	Xcode Project
File extension XCSL	CineStyle Color Correction File
File extension XCSNAPSHOTS	Xcode Snapshot
File extension XCU	OpenOffice.org Configuration File
File extension XCWORKSPACE	Xcode Workspace File
File extension XDB	Symantec Virus Database File
File extension XDI	WinArchiver Extended Disc Image File
File extension XDL	XML Schema File
File extension XDP	XML Data Package
File extension XDR	XML-Data Reduced File
File extension XDS	LCDStudio design file
File extension XDW	Fuji Xerox DocuWorks File
File extension XEF	WinAce Encrypted File
File extension XEJ	Expression Encoder Job File
File extension XEL	Expression Encoder Live Encoding File
File extension XEM	PowerDesigner Model definition File
File extension XEN	Guitar Hero III Data File
File extension XENSEARCH	XenCenter Saved Search File
File extension XEP	eManager File Packaging Information
File extension XER	Primavera P6 Project File
File extension XES	eManager Skins Definition
File extension XESC	Expression Encoder Screen Capture File
File extension XET	eManager Process Definition
File extension XEV	eManager Auto-Update File
File extension XEX	Xbox 360 Executable File
File extension XEZ	eManager Template Package
File extension XFD	XFD File
File extension XFDF	Adobe Acrobat XFDF File
File extension XFDL	XFDL File
File extension XFL	Flash Movie Archive
File extension XFN	Ventura Printer Font
File extension XFO	XSL-FO Formatted Form
File extension XFR	Ventura Publisher bitmap editor font file
File extension XFS	Gunbound file
File extension XFT	Adobe Form Designer 5.0 File
File extension XGML	Graph Modeling Language XML File
File extension XGMML	XGMML Graph File
File extension XGP	Xfire Game Patcher File
File extension XGS	XACT Global Settings File
File extension XHT	XHTML File
File extension XHTM	Extensible Hypertext Markup Language Document
File extension XHTML	Extensible Hypertext Markup Language File
File extension XI	Fasttracker 2 Extended Instrument File
File extension XIB	Interface Builder File
File extension XIF	ScanSoft Pagis File
File extension XISE	Xilinx ISE Project File
File extension XL	Excel Spreadsheet
File extension XLA	Excel Add-In File
File extension XLAM	Excel Open XML Macro-Enabled Add-In
File extension XLB	Excel Toolbars File
File extension XLC	Excel Chart
File extension XLD	Excel Database File
File extension XLF	XLIFF Document
File extension XLGC	ExpressK Database File
File extension XLIFF	XLIFF Localization File
File extension XLK	Excel Backup File
File extension XLL	Excel Add-In File
File extension XLM	Excel Macro
File extension XLMV	Thunder Mall video file
File extension XLNK	XML Shortcut File
File extension XLR	Works Spreadsheet
File extension XLS	Excel Spreadsheet
File extension XLSB	Excel Binary Spreadsheet
File extension XLSHTML	Microsoft Excel HTML Spreadsheet
File extension XLSM	Excel Open XML Macro-Enabled Spreadsheet
File extension XLSMHTML	Microsoft Excel MIME HTML Spreadsheet
File extension XLSX	Microsoft Excel Open XML Spreadsheet
File extension XLT	Excel Template
File extension XLTHTML	Microsoft Excel HTML Spreadsheet Template
File extension XLTM	Excel Open XML Macro-Enabled Spreadsheet Template
File extension XLTX	Excel Open XML Spreadsheet Template
File extension XLV	Excel Visual Basic Module
File extension XLW	Excel Workspace File
File extension XM	Fasttracker 2 Extended Module
File extension XMAP	XMind 2007/2008 Workbook
File extension XMB	Age of Empires Game Data File
File extension XMCD	Mathcad Worksheet File
File extension XMCDZ	Mathcad Compressed Worksheet File
File extension XMCT	Mathcad XML Worksheet Template
File extension XMD	Extended Media Disc Image
File extension XMF	Cal3D XML Mesh File
File extension XMI	XML Metadata Interchange File
File extension XMIND	XMind Workbook File
File extension XML	XML File
File extension XMLPER	LeCroy Binary Waveform File
File extension XMM	3ds Max XML Animation Map File
File extension XMMAP	MindManager XML Map File
File extension XMP	Extensible Metadata Platform File
File extension XMPZ	Miradi XML Project File
File extension XMV	Xbox Media Video File
File extension XMZ	FastTracker 2 Extended Module
File extension XNB	XNA Game Studio Binary Package
File extension XNK	Exchange Shortcut
File extension XNT	QuarkXPress Extension File
File extension XOF	Reality Lab 3D Image File
File extension XOL	Swiss Map Overlay
File extension XOM	Worms 3D Object File
File extension XOML	Windows Workflow File
File extension XP	WindowBlinds temporary file
File extension XP2	XPilot NG
File extension XP3	KiriKiri Package File
File extension XP4	KiriKiri Package
File extension XPADDERCONTROLLER	Xpadder Controller Profile
File extension XPD	XML Pipeline Document
File extension XPDL	XPDL Module
File extension XPG	Autoplay Media Studio Exported Page
File extension XPI	Mozilla Installer Package
File extension XPJ	RoboHelp HTML Project File
File extension XPK	PSpice library file
File extension XPL	X-Plane plug-in file
File extension XPM	X11 Pixmap Graphic
File extension XPP	X++ Source Code File
File extension XPR	Pro/ENGINEER Part Instance Accelerator File
File extension XPS	XML Paper Specification File
File extension XPT	Mozilla Firefox Component
File extension XQ	XQuery File
File extension XQL	XML Query Language File
File extension XQM	XQuery Module
File extension XQT	SuperCalc Macro File
File extension XQUERY	XQuery Source Code File
File extension XQY	XQuery Source File
File extension XRF	WordSearch cross reference file
File extension XRFF	Extensible Attribute-Relation File Format
File extension XRM-MS	Microsoft Security Certificate
File extension XRNS	Renoise Song File
File extension XRP	RationalPlan Project File
File extension XRY	XRY Data File
File extension XS	Age of Empires 3 Map AI Generator
File extension XSB	XACT Sound Bank
File extension XSC	Visual Studio Dataset Internal Info File
File extension XSD	XML Schema Definition
File extension XSF	InfoPath Form Definition File
File extension XSI	Softimage XSI 3D Image
File extension XSIADDON	Softimage Add-on File
File extension XSL	Microsoft SharePoint WorkSpace Groove database file
File extension XSLIC	XenServer License File
File extension XSLT	XSL Transformation File
File extension XSN	InfoPath Form Template File
File extension XSP	XBMC Smart Playlist File
File extension XSPF	XSPF Playlist File
File extension XSS	XML Style Sheet
File extension XST	Microsoft Outlook personal folders file
File extension XSVF	Xilinx Serial Vector Format File
File extension XSX	Visual Studio XML Schema Layout File
File extension XT	Xdebug Trace File
File extension XTG	QuarkXpress tags file
File extension XTL	Vietcong Data File
File extension XTM	CmapTools Exported Topic Map
File extension XTP	AutoCAD Exported Tool Palettes File
File extension XTREME	Winstep Xtreme Theme Pack
File extension XUI	Xbox 360 User Interface File
File extension XUL	XML User Interface Language File
File extension XUR	Xbox 360 Binary User Interface File
File extension XV0	Lattice XVL Structure File
File extension XV3	Lattice XVL Geometry File
File extension XVA	XenServer Virtual Appliance File
File extension XVCT	VISE XML Project File
File extension XVID	Xvid-Encoded Video File
File extension XVM	VMware Console Configuration File
File extension XVMCONF	World of Tanks XVM Configuration File
File extension XWB	XACT Wave Bank
File extension XWD	X Windows Dump Image
File extension XWF	OmniPage Workflow File
File extension XWK	Crosstalk Communicator Keyboard Mapping File
File extension XWP	XMLwriter Project
File extension XWS	Xara Web Designer Graphic
File extension XX	XXEncoded File
File extension XXD	Brixx Planner Calendar
File extension XXE	XXEncoded File
File extension XXX	Compucon Singer Embroidery File
File extension XY	XYWrite Document
File extension XY3	XYWrite III Document
File extension XYP	XYWrite Plus Document
File extension XYS	XYplorer Script File
File extension XYW	XYWrite for Windows Document
File extension XYZ	Molecule Specification File
File extension XYZV	Celestia Sampled Trajectory File
File extension XZ	XZ Compressed Archive
File extension XZFX	ZipLogix ZipForm File
File extension X_B	Parasolid Model Part File
File extension X_T	Parasolid Model Part File