File extension	The full name of the file	Popularity
File extension I	Visual Studio Intermediate File
File extension I00	DVD Shrink Part 1 File
File extension I01	DVD Shrink Part 2 File
File extension I02	DVD Shrink Part 3 File
File extension I3D	Houdini Image 3D File
File extension I3PACK	Point Blank Game Data File
File extension I5Z	IUCLID 5 Import/Export File
File extension IAA	INTUS Audio Archive
File extension IAF	Outlook Internet Account File
File extension IAM	Inventor Assembly File
File extension IAS	BitDefender file
File extension IB	InterBase Database
File extension IB2	IncrediBots 2 Saved Challenge File
File extension IB3	IncrediBots 3 Saved Challenge File
File extension IBA	iBooks Author Document
File extension IBATEMPLATE	iBooks Author Document Template
File extension IBB	ImgBurn Project File
File extension IBCD	InstantBingoCard Document
File extension IBOOKS	Multi-Touch iBook
File extension IBP	IsoBuster Managed Image Information File
File extension IBPLUGIN	Interface Builder Plug-in
File extension IBQ	IsoBuster Managed Image File
File extension IBRO	IncrediBots Robot File
File extension IBT	Texture and Model File
File extension IC1	Low Resolution Imagic Graphics File
File extension IC2	Medium Resolution Imagic Graphics File
File extension IC3	High Resolution Imagic Graphics File
File extension IC3D	IC3D Scene File
File extension ICA	Citrix ICA File
File extension ICAL	iCalendar File
File extension ICALENDAR	iCalendar File
File extension ICALEVENT	iCal Event File
File extension ICALTODO	iCal To Do File
File extension ICAP	InCopy Package File
File extension ICB	Targa ICB Bitmap Image
File extension ICBU	iCal Backup File
File extension ICC	ICC Profile
File extension ICD	Installable Client Driver File
File extension ICE	ICE File Archive
File extension ICF	Zoom Router Configuration File
File extension ICG	Image Comparer results file
File extension ICHAT	iChat Saved Chat Log
File extension ICL	Windows Icon Library File
File extension ICM	Image Color Matching Profile
File extension ICMA	InCopy Assignment File
File extension ICML	InCopy Document
File extension ICN	Windows Icon File
File extension ICNS	Mac OS X Icon Resource File
File extension ICO	Icon File
File extension ICON	Icon Image File
File extension ICONPACKAGE	IconPackager Theme File
File extension ICONTAINER	CandyBar iContainer File
File extension ICPR	IconUtils Project File
File extension ICR	Image Comparer Results File
File extension ICS	iCalendar File
File extension ICURSORFX	iCursor Effect File
File extension ID	Lotus Notes User ID File
File extension ID2	Windows Live Messenger Emoticon File
File extension IDAP	Adobe InDesign Assignment Package
File extension IDB	Visual Studio Intermediate Debug File
File extension IDC	Internet Database Connector File
File extension IDE	Borland C++ Project file
File extension IDEA	Adobe Ideas Document
File extension IDF	MIDI Instrument Definition File
File extension IDL	Interface Definition Language File
File extension IDLK	Adobe InDesign Lock File
File extension IDML	Adobe InDesign Markup Language File
File extension IDMS	Adobe InDesign Snippet
File extension IDPK	Adobe InDesign Package for GoLive File
File extension IDPP	Adobe InDesign Preflight Profile
File extension IDT	Windows Installer Database Text Archive File
File extension IDV	Inventor Design View File
File extension IDW	Inventor Drawing
File extension IDX	Index file
File extension IDX0	Runescape Cache Index File
File extension IDX255	Runescape Cache File
File extension IES	IES Photometric Data File
File extension IF	Procedimientos-Uno IFWin Project File
File extension IFAITH	iFaith SHSH File
File extension IFC	Industry Foundation Classes File
File extension IFCXML	Industry Foundation Classes XML File
File extension IFCZIP	Compessed IFC File
File extension IFD	InForm Document
File extension IFF	Interchange File Format
File extension IFL	3ds Max Image File List
File extension IFO	DVD-Video Disc Information File
File extension IFP	GTA Animation File
File extension IFS	InfoSlips Package
File extension IFW	INTUS Firmware File
File extension IGC	Anime List Builder Input File
File extension IGES	IGES File
File extension IGG	SuiteProfiler Color Map File
File extension IGM	Indigo Renderer Material File
File extension IGMA	INTUS Graph Mask Archive
File extension IGN	RoboHelp Ignore List File
File extension IGP	Igor Published Music Notation File
File extension IGR	SmartSketch drawing design file
File extension IGS	IGES Drawing File
File extension IGT	iGrafx Document Template
File extension IGX	iGrafx Document
File extension IHW	IN-HEH Timeline Workspace
File extension IHX	IN-HEH Timeline Database
File extension II	IconWorkshop Extended Information File
File extension IIF	Intuit Interchange Format File
File extension IIL	CleanSweep Installation Log
File extension IIM	iMacro Macro File
File extension IIP	ThinAnywhere configuration file
File extension IIQ	Phase One RAW Image
File extension IIT	Install Creator Project File
File extension IIX	Translation Memory Index File
File extension IK	CryENGINE IK Animation File
File extension IKF	INTUS Keyboard File
File extension ILBM	Interleaved Bitmap Image
File extension ILDOC	QuickSilver Document
File extension ILK	Incremental Linking File
File extension IMA	Generic disk image
File extension IMAGE	Apple Disk Image
File extension IMAPMBOX	IMAP Mailbox
File extension IMD	GIS Image Metadata File
File extension IME	Windows Input Method Editor File
File extension IMF	Id Music File
File extension IMG	Macintosh Disk Image
File extension IMG3	iPhone IMG3 File
File extension IMGA	Aleph One Image File
File extension IMI	Magellan Map File
File extension IMJ	JFIF Bitmap Image
File extension IML	IntelliJ IDEA Module
File extension IMMODULES	GTK+ Module File
File extension IMOVIEPROJ	iMovie Project File
File extension IMOVIEPROJECT	iMovie Project
File extension IMP	FileMaker Pro import data filter
File extension IMR	Impromptu Report File
File extension IMT	IMNET Graphics image file
File extension IMY	iMelody Ringtone File
File extension IMZ	WinImage Compressed Disk Image
File extension IN	Spyware File
File extension INC	Include File
File extension INCA	InCopy CS3 Assignment File
File extension INCD	InCopy Document
File extension INCP	InCopy CS3 Package File
File extension INCT	InCopy Template
File extension INCX	InCopy CS3 Interchange File
File extension IND	Adobe InDesign graphics document file
File extension INDB	Adobe InDesign Book File
File extension INDD	Adobe InDesign Document
File extension INDESIGNPLUGIN	Adobe InDesign Plug-in
File extension INDK	Adobe InDesign Shortcut Set File
File extension INDL	Adobe InDesign Library
File extension INDP	Adobe InDesign CS3 Package File
File extension INDS	Adobe InDesign Snippet File
File extension INDT	Adobe InDesign Template
File extension INETLOC	Internet Location
File extension INF	Setup Information File
File extension INFO	ZoomBrowser Image Index File
File extension INFOPATHXML	Microsoft InfoPath Form
File extension INF_LOC	Windows Driver Information Cache File
File extension ING	MasterCook Ingredients File
File extension INI	Windows Initialization File
File extension INK	Mimio Ink Data File
File extension INL	C++ Inline File
File extension INLK	Adobe InDesign Lock File
File extension INM	FaxMaster Document
File extension INMS	Adobe InDesign Menu Set File
File extension INO	Inno Setup script file
File extension INP	Abaqus Input File
File extension INPROGRESS	Time Machine Backup Progress File
File extension INS	Internet Settings File
File extension INT	SGI Integer Image
File extension INTERNETCONNECT	Apple Internet Connect Document
File extension INV	INVedit File
File extension INX	Adobe InDesign Interchange File
File extension IOBIT	Advanced SystemCare Rollback File
File extension ION	File Description File
File extension IOPLIST	Mac OS X IOPLIST File
File extension IP	IconPackager Theme File
File extension IPALIAS	iPhoto Alias File
File extension IPCC	iPhone Carrier Bundle
File extension IPCH	Intellisense Precompiled Header File
File extension IPD	BlackBerry Backup File
File extension IPF	SMS Installer Script
File extension IPG	iPod Game File
File extension IPHOTO	iPhoto Library File
File extension IPHOTOPROJECT	iPhoto Print Project
File extension IPICK	iPick Football Image
File extension IPJ	Inventor Project File
File extension IPK	Shana Informed Filler file
File extension IPL	CorelDRAW Pantone spot reference palette file
File extension IPLB	iPhoto Library Archive Document
File extension IPMETA	Apple iPhoto Metadata File
File extension IPN	Inventor Presentation File
File extension IPOD	Rockbox Firmware File
File extension IPP	Inline Guard Macro File
File extension IPR	IntelliJ project XML data file
File extension IPROJECT	iClone Project File
File extension IPS	Internal Patching System Patch File
File extension IPSPOT	iPhoto Spot File
File extension IPSW	iPod and iPhone Software Update File
File extension IPT	Inventor Part File
File extension IPTHEME	IconPackager Raw Theme File
File extension IPX	IPIX Image
File extension IQY	Internet Query
File extension IRCP	SpeedGrade IRIDAS Composite File
File extension IRF	Autodesk Impression drawing file
File extension IROCK	intelliRock Sensor Data File
File extension IROS	Adobe Save For Web Settings File
File extension IRP	Microsoft ISA Server Report Generator output file
File extension IRR	UVBrewer brewer lamp file
File extension IRS	Adobe Save For Web Settings
File extension IRX	Brewer Irradiation File
File extension IS1	SmartWare input screen file
File extension ISC	Xilinx Device Configuration File
File extension ISD	Flexera InstallShield Dialog Box File
File extension ISE	InstallShield Express Project File
File extension ISF	Inspiration Flowchart Document
File extension ISH	ISH Compressed Archive
File extension ISH1	Animation-ish Wiggledoodle-ish Document
File extension ISH2	Animation-ish FlipBook-ish Document
File extension ISH3	Animation-ish Advanced-ish Document
File extension ISM	InstallShield project file
File extension ISMA	IIS Smooth Streaming Audio File
File extension ISMC	Smooth Streaming Client Manifest File
File extension ISMCLIP	iStopMotion Animation Clip
File extension ISMV	IIS Smooth Streaming Video File
File extension ISN	Installer Source Files
File extension ISO	Disc Image File
File extension ISOZ	Compressed Arbortext IsoDraw Illustration
File extension ISP	IIS Internet Service Provider Settings
File extension ISPC	Image Surfer Pro Collection File
File extension ISR	InstallShield uninstall information file
File extension ISS	ISS picture image file
File extension IST	Adobe ImageStyler file
File extension ISU	InstallShield uninstall script file
File extension ISZ	Zipped ISO Disk Image
File extension IT	Impulse Tracker Module
File extension ITA	IconTweaker Theme Archive
File extension ITC	iTunes Cover Flow Data File
File extension ITC2	iTunes Cover Flow Data File 2
File extension ITDB	iTunes Database File
File extension ITE	iTunes Extras File
File extension ITEMDATA-MS	Windows 8 Start Screen Item Data File
File extension ITHMB	iPod and iPhone Photo Thumbnails File
File extension ITI	Impulse Tracker Instrument
File extension ITK	ScummVM Game Data File
File extension ITL	iTunes Library File
File extension ITLP	iTunes LP Album File
File extension ITLS	iTunes Live Stream URL
File extension ITM	iThink Model File
File extension ITMS	iTunes Music Store Link File
File extension ITMSP	iTunes Store Package
File extension ITN	TomTom Navigator Itinerary File
File extension ITPC	iTunes Podcast Link File
File extension ITR	Icy Tower Replay File
File extension ITS	Impulse Tracker Sample
File extension ITT	IconTweaker Theme File
File extension ITW	InTouch With Database File
File extension ITX	ITX Form Template
File extension IUP	Fritz Update File
File extension IUS	InfoTMIC Firmware Update File
File extension IV	Open Inventor Scene Graph File
File extension IV2I	Norton Ghost Incremental Virtual Volume Image
File extension IVA	Surveillance Video File
File extension IVC	iView MediaPro catalogue file
File extension IVD	Bitdefender Incremental Virus Definitions File
File extension IVE	OpenSceneGraph Binary File
File extension IVF	Indeo Video Format File
File extension IVR	Internet Video Recording
File extension IVS	Internet streaming video
File extension IVT	Beyond 20/20 Table File
File extension IVUE	Live Picture IVUE Image
File extension IW	Chain Engineering Database File
File extension IWD	Call of Duty Game Data File
File extension IWDGT	iWeb Widget File
File extension IWI	Infinity Ward Texture File
File extension IWS	Trojan-Downloader.JS.Agent file
File extension IWXDATA	iWorx Data File
File extension IWZ	InstallShield Express 2 Project File
File extension IX	dtSearch Index File
File extension IX2	WordPerfect Address Book File
File extension IXA	Ulead Disc Image format
File extension IXB	Ulead Disc Image
File extension IZE	IZArc Archive
File extension IZZ	Isadora Media Control Project
File extension IZZY	Isadora Project