letter I extensions

.I Progress Include File
.IAF MS Outlook 97 and 2000 E-mail Account Settings
.IAN Sterling Software COOL Business Team Model File Sterling merged with Computer Associates.
.IBA MDE InfoHandler Infobase File
.IBM Image File
.ICA Citrix File IOCA Graphics File
.ICB Targa Bitmap
.ICC Kodak Printer Image
.ICE Archive File
.ICL Icon Library File (various) ImageForge/IconForge [Viewer]
.ICM Image Color Matching Profile File
.ICN Icon Program
.ICO Icon [Viewer]
.ICS Outlook Calendar File
.ID Disk Identification File
.IDB MS Developer Intermediate File
.IDD MIDI Instrument Definition
.IDE Integrated Development Environment Configuration File
.IDF MIDI Instruments Drivers File
.IDQ Internet Data Query File
.IDW Aldus IntelliDraw Vector Graphic
.IDX Index (multiple programs)
.IEF Image File
.IES Photometric File Data [Illuminating Engineering Society]
.IFD Jet Form Design Form
.IFF Graphic, Sound (Interchangeable File Format) [Viewer]
.IFS OS/2 System File IconForge Image EXE Library
.IGF Inset Systems Metafile
.IGS IGES-Format
.IIF QuickBooks for Windows Interchange File
.III Intel Phone Compatible
.IL Icon Library
.IM8 Sun Raster Graphic
.IMA WinImage File
.IMF ImageForge/ImageForge Image EXE Library
.IMG Bitmap Graphic (several programs) [Viewer] CloneCd Related File
.IMP Urban Chaos Game File Lotus Improv Spreadsheet
.IN3 Harvard Input Device Driver (Harvard Graphics taken over by Serif)
.INC Include File (various)
.IND dBase IV or DataPerfect Index
.INF Information or Setup File
.INI Initialization file (many)
.INK Pantone Reference File Mimio Ink File [Electronic Whiteboard]
.INL MS Visual C++ Inline Function File
.INP Oracle Source Code
.INS Internet Communication Setting WordPerfect File Ensoniq EPS Family Instrument Sample Cell / II Instrument InstallShield Script X-Internet Sign-up File Inspiration Mind Mapping Software File
.INT Borland Interface Units Foxpro Code Page Intermediate Code used for syntax checking (various)
.INX Foxbase Index
.IO Compressed Archive
.IOB Imagine File
.IOF Findit Document
.ION Text Program/Installation Description
.IPD InstallPROG 6 EDBS Install Database
.IPF Microsoft SMS Installer Script (with System Management Server 2.0)
.IPL Corel Pantone Spot Reference Palette InstallPROG 6 EDBS File Library
.IPX Interactive Pictures Corporation AV File
.IQY Excel Web Query
.IRS WordPerfect Resource File
.ISD RapidFile Dictionary
.ISH Compressed Archive File
.ISO File List for CD-ROM
.ISP X-Internet Sign-up File Internet Communication Settings
.ISS InstallShield Response File
.IST Digitrakker Instrument File (by n-FaCToR)
.ISU InstallShield Uninstall Script Netscape File
.IT Impulse Tracker Music Module
.ITI Impulse Tracker Instrument
.ITS Internet Document Set Impulse Tracker Sample
.IV VRML File Open Inventor File
.IVF Indeo Video File
.IW Iconware Application Idlewild Screensaver
.IWA IBM Writing Assistant Text
.IWC Installwatch Database (install monitor)
.IWP Wang Text File
.IX Framemaker Index File Paperport Search File