# File Extensions File types with extensions that start with a number or symbol. Extension File Type File Description .!ut Misc uTorrent Incomplete Download .$$$ Backup Temporary File .$01 Developer DOS Pipe File .$db Backup dBASE Temporary File .$er Data GroupWise Database .0 Compressed Hacha Split Archive File .0 Game M3 DS Real Save File .000 Misc Windows CE Installation Data File .000 Disk Virtual CD ISO File .000 Compressed DoubleSpace Compressed File .001 Image Fax File .001 Backup HJSplit Split Archive .001 Misc 001 File Manager Split File .001 Developer Multimedia Fusion Backup File .001 Game Snes9x Slot 2 Saved State .001 Backup Norton Ghost Disk Backup .001 Misc 001 File Joiner & Splitter File .001 Misc SplitJoin Split File .0xe Executable F-Secure Renamed Virus File .113 Backup Iomega Backup File .123 Data Lotus 1-2-3 Spreadsheet .123 Data PCB123 Circuit Board Design .1pe Data TurboTax Form File .1ph Data TurboTax File .1st Text Readme File .256 Settings Descent 2 Color Palette File .2bp Raster Image Pocket PC Bitmap Image File .2d Image VersaCAD 2D Drawing .2mg Disk Apple IIGS Disk Image .386 System Windows Virtual Device Driver .3d Image Stereo CAD-3D Image File .3d2 Image Stereo CAD-3D 2.0 Image File .3d4 3D Image Stereo CAD-3D 2.0 Image File .3da Image 3D Assembly .3df 3D Image 3D Format .3dl 3D Image LightConverse 3D Model File .3dm 3D Image Rhino 3D Model .3dmf 3D Image QuickDraw 3D Metafile .3dr Data 3DMark Results File .3ds 3D Image 3D Studio Scene .3dt Data 3D Topicscape File .3dv 3D Image 3D VRML World .3dx 3D Image Rhino 3D Model File .3dxml 3D Image Dassault Systemes 3D XML File .3g2 Video 3GPP2 Multimedia File .3gp Video 3GPP Multimedia File .3gp2 Video 3GPP Multimedia File .3gpp Video 3GPP Media File .3me Data TurboTax Form File .3mm Video 3D Movie Maker Movie Project .3p2 Video 3GPP Multimedia File .3pe Data TurboTax 2008 Form File .411 Raster Image Mavica Thumbnail Image .4db Developer 4th Dimension Database Structure File .4dd Developer 4th Dimension Database Data File .4dl Data 4th Dimension Database Log File .4dv Data 4D View Ultrasound File .4mp Audio 4-MP3 Database File .60d Video CCTV Video Clip .669 Audio UNIS Composer 669 Module .6cm Audio Six Channel Module .7z Compressed 7-Zip Compressed File .83p Misc TI-83 Calculator File .8ba Plugin Photoshop Plug-in .8bc Plugin Photoshop 5.0 Plug-in .8be Plugin PhotoDeluxe Plug-in .8bf Plugin Filter Factory Image Filter .8bf Plugin Photoshop Filter Plug-in .8bi Plugin Photoshop Plug-in .8bi8 Plugin Photoshop Plug-in .8bl Plugin Photoshop Plug-in .8bs Plugin Photoshop 5.0 Selection Plug-in .8bx Plugin PhotoDeluxe Plug-in .8by Plugin PhotoDeluxe Plug-in .8cm Audio Eight Channel Module .8li Plugin Photoshop Scripting Plug-in .8med Audio Amiga OctaMed Music File .8pbs Image Adobe Photoshop Macintosh File .8st Settings 8start Launcher File .8svx Audio Amiga 8-Bit Sound File .8xg Data TI-83/84 Plus Group File .8xi Raster Image TI-83/84 Plus Picture File .8xk Data TI-83 Plus Application Upgrade File .8xp Misc TI-83 Plus Calculator File .8xs Data TI-83/84 Plus String File .8xu System TI-83 Plus Operating System File .8xv Data TI-83/84 Plus Variable File .^^^ Data Pervasive.SQL Database File .{pb Data Corel WordPerfect Document Index File .~hm Data HostMonitor TestList Backup File A File Extensions File types with extensions that start with the letter A. Extension File Type File Description .a Developer Static Library .a00 Compressed ALZip Second Split Archive File .a01 Compressed ALZip Third Split Archive File .a02 Compressed ALZip Fourth Split Archive File .a2m Audio AdLib Tracker 2 File .a2m Settings TS-AudioToMIDI Settings File .a2w Developer Alice World .a3l Data Authorware 3 Library .a3m Data Authorware 3 Macintosh File .a3w Data Authorware 3 Windows File .a4l Data Authorware 4 Library .a4m Data Authorware 4 Macintosh File .a4w Data Authorware 4 Windows File .a5l Data Authorware 5 Library .a5w Data Authorware 5 Windows File .a65 Data Authorware 6.5 File .a6p Executable Authorware 6 Program .aa Disk Generic CD Image .aa Audio Audible Audio Book File .aa3 Audio ATRAC Audio File .aac Audio Advanced Audio Coding File .aam Settings Authorware Map File .aao Data Agenda At Once File .aao Game America's Army Map File .aawdef Misc Ad-Aware Definitions File .aax Audio Audible Enhanced Audiobook File .ab Developer Applix Builder File .ab Data DNA Sequence File .ab1 Data DNA Electropherogram File .ab2 Data Print Shop Address Book File .ab3 Data PhotoImpact 3 Album File .aba Backup Palm Address Book Archive .aba Plugin Avant Browser Add-on File .abbu Backup Address Book Backup .abc Developer ABC Source File .abc Audio ABC Music Notation .abcd Data AudioVisual Book Data File .abf Font Adobe Binary Screen Font File .abi Data DNA Chromatogram File .abk Backup Automatic Backup File .abk Game Arena Opening Book File .abk Game Need for Speed Underground Audio File .abm Audio Music Album .abm Raster Image Photo Album .abp Data AVS Barcode Profile .abr Misc Adobe Photoshop Brushes File .abw Text AbiWord Document .aby Data AOL Address Book File .ac Executable Autoconf Script .ac$ Misc AutoCAD Temporary File .ac3 Audio Audio Codec 3 File .ac5 Image ArtCut 5 Document .ac6 Image ArtCut 6 Document .aca Data Agent Character Animation File .acb Misc AOL Cab Launcher .acc Data Graphics Accounts Data File .accdb Data Access 2007 Database File .acd Audio ACID Project File .acd Developer RSLogix 5000 Program .ace Compressed WinAce Compressed File .acf Data Agent Character Data File .acfm Font Adobe Composite Font Metrics File .acg Data Agent Preview File .acl Misc AutoCorrect List File .acm Audio Interplay Audio File .acr Backup Acer eRecovery Management Backup File .acr Image American College of Radiology Format .acr Executable ACRobot Script .acrobatsecuritysettings Settings Adobe Acrobat Security Settings File .acrodata Settings Acrobat Data File .acs Misc Agent Character File .acsm Misc Adobe Content Server Message File FoxPro Documenting Wizard Action .act Text Diagram .act 3D Image Genesis3D Actor File .act Audio ADPCM Compressed Audio File .action Executable Automator Action .acx Game Atari ST Program .ad Misc After Dark Screensaver .ada Developer Ada Source Code .adb Developer Ada Body File .adb Developer Alpha Five Database File .adc Image Scanstudio 16 Color Image .add Misc Dynamics AX Developer Documentation File .ade Data Access Project Extension .adf Disk Amiga Disk File .adg Audio Ableton Device Group Dynamics AX Developer Documentation .adi Misc Index File AutoCAD Device-Independent Binary Plotter .adi Image File .adm Misc Portfolio Admin-Level Access Flag .adm System Administrative Template File .adp Data Access Project .adr Web Opera Bookmarks File .ads Developer Ada Specification File .adt Text AutoCAD Audit Log .adt Data ACT! Document Template .adx Data Approach Index File .adz Disk Compressed Amiga Disk File .aea Settings Ae Timer Alarm Document .aep Developer Activ E-Book Project .aep Video After Effects Project .aex Web Alpha Five Compiled Global Functions File .afc Audio Mass Effect 2 Audio File .afm Font Adobe Font Metrics File .afp Encoded FileProtector Encrypted File .afp Page Layout Advanced Function Presentation File .afploc Misc Apple Filing Protocol Location .afs Data STAAD.foundation Project File .aft Data Ancestry.com Family Tree Database .afx Raster Image Auto FX Photo/Graphic Edges Image .agd Data AgileGraph Data File .agd Misc Agile Advantage E-mail Attachment .agi Developer Asterisk Gateway Interface File .agif Raster Image Active GIF Creator Project .agm Audio DTS Multi-channel Pro Packer File .agp Raster Image ArtGem Project File .ahd Misc Dynamics AX Online Help Data File .ahi Misc Dynamics AX Online Help Index File .ahk Executable AutoHotkey Script .ahl Settings eMule Metadata File .ahs Settings Adobe Halftone Screen File .ahx Audio WinAHX Tracker Module .ai Vector Image Adobe Illustrator File .aic Raster Image Advanced Image Coding File .aif Audio Audio Interchange File Format .aif Misc Symbian Application Information File .aifb Data AIF Builder Project File .aifc Audio Compressed Audio Interchange File .aiff Audio Audio Interchange File Format .aim Text AIMMS ASCII Model File .aim Misc AOL Instant Messenger Launch File .ain Compressed AIN Compressed File Archive .aip Plugin Illustrator Plug-in .air Executable Adobe AIR Installation Package .ais Audio Velvet Studio Instrument .ais Raster Image ACDSee Image Sequence File .ait Settings Adobe Illustrator Template .ajp Video CCTV Video File .akp Audio Akai Sampler File .al Audio A-Law Compressed Sound Format .alaw Audio A-Law Compressed Sound Format .alb Developer Alpha Five Library .albm Raster Image HP Photo Printing Software Album File .alc Data Dynamics AX Label Description File .ald Data Dynamics AX Application Label Data File .ali Data Dynamics AX Label Index File .all Audio Cubasis Project File .alt Misc Dynamics AX Temporary File .alx Settings BlackBerry Application Loader XML File .alx Web ActiveX Layout Control File .alz Compressed ALZip Archive .am1 Game Adventure Maker .am4 Developer AutoPlay Media Studio 4 Project File .am5 Developer AutoPlay Media Studio 5 Project File .am6 Developer AutoPlay Media Studio 6 Project .am7 Developer AutoPlay Media Studio 7 Project .amb Data AIMMS Model File .amf Audio Advanced Module File .amfm Font Adobe Multiple Font Metrics File .amr Audio Adaptive Multi-Rate Codec File .ams Settings Adobe Monitor Setup file .ams Audio Velvet Studio Module .ams Audio Extreme Tracker Module .amsorm Data OnLine Ringman Auction Client File .amu Image Sony Photo Album