| .a | Unix Static Object Code Library Format |
| .a$v | QuarkXpress Automatically Saved Project |
| .a00 | Split Multi-volume ARJ Compressed File Archive (part 2) |
| .a01 | Split Multi-volume ARJ Compressed File Archive (part 3) |
| .a02 | Split Multi-volume ARJ Compressed File Archive (part 4) |
| .a03 | Split Multi-volume ARJ Compressed File Archive (part 5) |
| .a04 | Split Multi-volume ARJ Compressed File Archive (part 6) |
| .a05 | Split Multi-volume ARJ Compressed File Archive (part 7) |
| .a06 | Split Multi-volume ARJ Compressed File Archive (part 8) |
| .a07 | Split Multi-volume ARJ Compressed File Archive (part 9) |
| .a08 | Split Multi-volume ARJ Compressed File Archive (part 10) |
| .a09 | Split Multi-volume ARJ Compressed File Archive (part 11) |
| .a1 | Free Pascal Archive |
| .a10 | Split Multi-volume ARJ Compressed File Archive (part 12) |
| .a11 | Split Multi-volume ARJ Compressed File Archive (part 13) |
| .a12 | Split Multi-volume ARJ Compressed File Archive (part 14) |
| .a13 | Split Multi-volume ARJ Compressed File Archive (part 15) |
| .a14 | Split Multi-volume ARJ Compressed File Archive (part 16) |
| .a15 | Split Multi-volume ARJ Compressed File Archive (part 17) |
| .a16 | Split Multi-volume ARJ Compressed File Archive (part 18) |
| .a17 | Split Multi-volume ARJ Compressed File Archive (part 19) |
| .a18 | Split Multi-volume ARJ Compressed File Archive (part 20) |
| .a19 | Split Multi-volume ARJ Compressed File Archive (part 21) |
| .a1wish | Audials Wishlist Format |
| .a20 | Split Multi-volume ARJ Compressed File Archive (part 22) |
| .a21 | Soundweb Firmware |
| .a26 | Atari 2600 ROM Image Format |
| .a2a | IBM Voice Type Languages Vocabels |
| .a2b | Adlib Tracker II Instrument Bank |
| .a2c | Alice Scene Format |
| .a2desktop | Aston Desktop Desktop Skin |
| .a2i | Adlib Tracker Instrument Format |
| .a2l | ASAP2 Description Format |
| .a2m | AdLib Tracker 2 Format |
| .a2menu | Aston Desktop Start Menu Skin |
| .a2p | Adlib Tracker Pattern Format |
| .a2panel | Aston Desktop Panel Skin |
| .a2r | KittyXplorer Encrypted Archive |
| .a2t | Adlib Tracker Tiny Module Format |
| .a2theme | Aston 2 Theme Format |
| .a2w | Alice Program World Format |
| .a31 | Adobe Authorware Library |
| .a32 | Split Multi-volume ARJ Compressed File Archive (part 34) |
| .a3d | Amapi 3D Modeling |
| .a3g | Photo! 3D Gallery |
| .a3k | Yamaha A3000 Sampler |
| .a3l | Adobe Authorware Library Format |
| .a3m | Adobe Authorware Unpackaged Format |
| .a3p | Alice 3 Project |
| .a3s | Yamaha A3000 Sample |
| .a3w | Adobe Authorware Unpackaged Format |
| .a3x | AccuLoad III.net Settings |
| .a41 | Adobe Authorware Library |
| .a4l | Adobe Authorware Library Format |
| .a4m | Adobe Authorware Unpackaged Format |
| .a4p | Adobe Authorware Package Without Runtime |
| .a4r | Adobe Authorware Package Course |
| .a4w | Adobe Authorware Unpackaged Format |
| .a51 | Adobe Authorware Library |
| .a52 | Atari 5200 Game Image Format |
| .a5d | Adobe Authorware Model |
| .a5l | Adobe Authorware Library Format |
| .a5m | Adobe Authorware Unpackaged |
| .a5p | Adobe Authorware Package Without Runtime |
| .a5r | Adobe Authorware Packaged File Without Runtime |
| .a5rpt | Alpha Five Project Report |
| .a5w | Adobe Authorware Unpackaged Format |
| .a5wcmp | Alpha Five Web Publishing |
| .a64 | Artist 64 |
| .a65 | Adobe Authorware Library Format |
| .a66 | µVision Assembler Source |
| .a6d | Adobe Authorware Model |
| .a6l | Adobe Authorware Library |
| .a6m | Adobe Authorware Unpackaged |
| .a6p | Adobe Authorware Application Format |
| .a6r | Adobe Authorware Packaged File Without Runtime |
| .a6w | Adobe Authorware Unpackaged |
| .a78 | Atari 7800 Image |
| .a7d | Adobe Authorware Model |
| .a7e | Adobe Authorware Packaged Library |
| .a7l | Adobe Authorware Library |
| .a7m | Adobe Authorware Unpackaged |
| .a7p | Adobe Authorware Packaged File Without Runtime |
| .a7r | Adobe Authorware Packaged File Without Runtime |
| .a7w | Adobe Authorware Unpackaged |
| .a86 | A86 Assembly Language Source Code |
| .a8s | Anim8or Script Format |
| .aa | Audible Audio Format |
| .aa3 | Sony ATRAC Audio Format |
| .aaa | Sybase SQLAnywhere Temporary |
| .aab | Adobe Authorware Binary |
| .aac | Advanced Audio Coding Format |
| .aad | FreeBSD |
| .aaf | Advanced Authoring Format Multimedia Format |
| .aam | Adobe Authorware Shocked Format |
| .aao | Agenda At Once Format |
| .aap | Apollo Advanced Playlist |
| .aapkg | ArchestrA IDE Package |
| .aar | Apache Axis2 Archive |
| .aas | Adobe Authorware Shocked Packet |
| .aat | ArcInfo Line Data |
| .aatrend | ActiveFactory Trend |
| .aaui | Adobe Acrobat UI Settings Format |
| .aaw | Lavasoft Ad-Aware 2007 Settings |
| .aawdef | Ad-Aware Definitions Format |
| .aax | Audible Enhanced Audio Format |
| .ab | Google Android Debug Bridge Backup Format |
| .ab$ | Autodesk AutoCAD Plot Spooling |
| .ab1 | DNA Electropherogram Format |
| .ab2 | Print Shop Address Book File |
| .ab3 | Photoimpact 3 Album Format |
| .ab4 | AB4 Accounting & Business Data |
| .ab6 | ABStat Data |
| .ab65 | Adobe PageMaker Document |
| .ab8 | ABStat Data |
| .aba | Palm Address Book Archive Format |
| .abbu | Apple Address Book Archive Format |
| .abc | Musical Notation Language Format |
| .abcd | AudioVisual Book Data Format |
| .abcddb | Apple Address Book Database |
| .abcdg | Apple AddessBook |
| .abcdmr | Apple Address Book Mail Recent |
| .abcdp | Address Book Card Data |
| .abd | The Bat! Mail Processing System |
| .abdata | Adobe Bridge Data Format |
| .abe | Application Boundaries Enforcer |
| .abf | Adobe Binary Screen Font Format |
| .abg | FIFA World Cup Game Data Beart |
| .abi | Chromatogram Editor Format |
| .abicollab | AbiWord Collaborative File Descriptor |
| .abk | Ability Write Backup Format |
| .abkprj | Ashampoo Burning Studio Backup Project Format |
| .abl | ABEL Hardware Description Language |
| .abm | Music Album Format |
| .abn | Alpha Five |
| .abp | AVS Barcode Profile |
| .abr | Adobe Photoshop Brush Format |
| .abs | Absolute Database Single-file Database Format |
| .abt | The Arbiter Game Schedule |
| .abu | ACT! E-mail Address Book |
| .abw | AbiWord Document Format |
| .abx | Corel WordPerfect Mail Address Book |
| .aby | AOL Directory Format |
| .abz | Alpha Black Zero Game |
| .ac | AC3D Geometry Format |
| .ac$ | AutoCAD Undo Info Format |
| .ac0 | SPICE AC/frequence Domain Output |
| .ac1 | SPICE AC/frequence Domain Output |
| .ac2 | SPICE AC/frequency Domain Output |
| .ac3 | Dolby Digital Sound Format |
| .ac3d | 3d Format Data |
| .ac4 | SPICE AC/frequence Domain Output |
| .ac5 | ArtCut 5 Document Format |
| .ac6 | Artcut Software Graphics Design Format |
| .ac7 | SPICE AC/frequence Domain Output |
| .ac8 | SPICE AC/frequence Domain Output |
| .ac9 | SPICE AC/frequence Domain Output |
| .aca | Microsoft Agent Character Format |
| .aca2 | Fontographer |
| .acad | AutoCAD Database |
| .acb | Adobe Color Book Format |
| .acbl | Adobe Color Book Format |
| .acc | DR DOS - ViewMax Format |
| .accda | Microsoft Access 2007/2010 Add-in Format |
| .accdb | Microsoft Access 2007/2010 Database Format |
| .accdc | Microsoft Access 2007/2010 Digitally Signed Database Format |
| .accde | Microsoft Access 2007/2010 Compiled Execute Only Format |
| .accdp | Microsoft Access 2007/2010 Project |
| .accdr | Microsoft Access 2007/2010 Runtime Mode Database Format |
| .accdt | Microsoft Access 2007/2010 Database Template Format |
| .accdu | Microsoft Access 2007/2010 Database Wizard Format |
| .accdw | Microsoft Access Link Format |
| .access | Java Access Control |
| .accessor | Microsoft Visual Studio Accessor |
| .accfl | Microsoft Access Field Template |
| .accft | Microsoft Access Template Format |
| .accountpicture-ms | Microsoft Windows 8 Account Picture Format |
| .acct | IBM AIX System |
| .acd | Sonic Foundry ACID Audio Format |
| .acd-bak | Sony ACID Project Backup Format |
| .acd-zip | Sony ACID Compressed Project Format |
| .ace | WinACE Compressed Ace Archive Format |
| .acf | Microsoft Agent HTTP Character Format |
| .acfm | Adobe Composite Font Metrics Format |
| .acg | Age Of Wonders Saved Game |
| .acgd | ACG System Predictive Model |
| .acgi | ACGI Script (WWW) |
| .acgl | ACG System Licence |
| .ach | Medlin Payroll Software Automated Clearing House |
| .aci | ACI Development Appraisal |
| .ack | Swifty |
| .acl | Microsoft Office Automatic Correction List |
| .aclock | Amazing Clock |
| .acm | ACM Compressed Sound Format |
| .acmd | Apache Commander Project |
| .aco | Adobe Photoshop Color Palette And Swatches Format |
| .acorn | Acorn Draw Format |
| .acp | Alfresco Exported Repository Format |
| .acq | AcqURL Bookmark Manager |
| .acr | Bitmap Graphics |
| .acrobatsecuritysettings | Adobe Acrobat Security Settings Format |
| .acrodata | Adobe Acrobat Data Format |
| .acroplugin | Adobe Acrobat Plug-in Format |
| .acrs | Adobe Authorware |
| .acrypt | AutoCrypt Encrypted Document |
| .acs | Microsoft Agent Character Structured Storage Format |
| .acs2 | AIMP Media Player Skin |
| .acs3 | AIMP Skin Package |
| .acsm | Adobe Content Server Message Format |
| .act | Adobe Photoshop/Illustrator Color Table |
| .act! | ACT! |
| .action | Mac OS X Automator Action Format |
| .actions | Photoline 4 Defaults |
| .actionScriptProperties | Adobe Flex Settings |
| .activitydiagram | Microsoft Visual Studio Activity Diagram |
| .actm | Autodesk AutoCAD Action Macro Format |
| .actproj | Microsoft Visual Studio Visual SourceSafe ACT Project |
| .actx | DS Game Maker Action Description Format |
| .acu | Machine Independent COBOL Object |
| .acv | Adobe Photoshop Colour Curves Format |
| .acw | Microsoft Accessibility Wizard Format |
| .acx | Atari ST Program Format |
| .ad | After Dark Screen Saver Format |
| .ad1 | Forensic Toolkit FTK Imager Image |
| .ad3e | Adobe Dimensions Mac |
| .ad65 | PageMaker 6.5 |
| .ada | ADA Language Source Code Format |
| .adadownload | Adobe Download Assistant Partially Completed Download |
| .adb | Ability Database Database Format |
| .adba | AIMSS Author Project Configuration |
| .adblock | Alpha Five Temporary |
| .adc | Lingvo Dictionary Format |
| .adcp | Adobe Device Centra Project |
| .add | Microsoft Dynamics AX Developer Documentation Format |
| .addin | Microsoft Visual Studio Addin Format |
| .addon | CFS Console Add-on Format |
| .addr | Metin2 Data |
| .ade | Microsoft Access Compiled Project Format |
| .adf | ArcView ARC/INFO Coverage Data Format |
| .adg | Ableton Live Device Group Format |
| .adh | Audible Manager |
| .adi | Active@ Disk Image Format |
| .adiumemoticon | Adium Dock Icon |
| .adiumemoticonset | Adium Emoticon Set |
| .adiumhtmllog | Adium HTML Log |
| .adiumicon | Adium Icon |
| .adiumlibpurpleplugin | Adium Lib Purple Plugin |
| .adiumlistlayout | Adium List Layout |
| .adiumlisttheme | Adium List Theme |
| .adiumlog | Adium Log |
| .adiummenubaricons | Adium Menu Bar Icon |
| .adiummessagestyle | Adium Message Style |
| .adiumplugin | Adium Plugin |
| .adiumscripts | Adium AppleScripts |
| .adiumserviceicons | Adium Service Icons |
| .adiumsoundset | Adium Sound Set |
| .adiumstatusicons | Adium Status Icon |
| .adj | LISCAD Adjustment |
| .AdjustmentPresets | Apple Aperture Preset |
| .adk | OS/2 Saved SKF Format |
| .adl | ADONIS Models And Model Groups Export |
| .adls | ADL Workbench |
| .adm | Administrator Policy Template Format |
| .adml | Microsoft Administrative Language-specific XML Template Format |
| .admx | Microsoft Administrative XML Template Format |
| .adn | Microsoft Access Blank Project Template |
| .ado | Adobe Photoshop Duotone Format |
| .adobebridge | Adobe Bridge |
| .adobenet | Adobe Production Studio |
| .adoc | Authentica Secure Office Encoded Word Document |
| .ados | Compound Document |
| .adox | ActivDox Document Format |
| .adp | Microsoft Access Project Format |
| .adpp | Adobe Device Central Package Profile |
| .adr | Opera Bookmarks Format |
| .adrg | ARC Digitized Raster Graphics |
| .ads | Ada Package Specification |
| .adsk | Autodesk Exchange |
| .adsm | Advanced Split Machine Split |
| .adt | Lingvo Dictionary Format |
| .adtg | Advanced Data TableGram |
| .adts | Audio Data Transport Stream |
| .adu | Dictionary Format |
| .adv | Nortek Acoustic Doppler Velocimeter Format |
| .advs | Adobe Device Central Format |
| .adw | Tamil Transliterater/font Converter |
| .adx | Approach Database Index Format |
| .adz | Amiga Emulator Compressed ADF Format |
| .ad_asm | Alibre Design CAD |
| .ad_prt | Alibre Design CAD |
| .ae0 | NetBSD Ethernet Configuration |
| .ae1 | FileMaker Pro Runtime Database |
| .aea | Ae Timer Alarm Document Format |
| .aeb | Alphacam Wire EDM VB Macro |
| .aec | DataCAD Drawing Format |
| .aed | Alphacam Wire EDM Drawing |
| .aee | ASUS Data Security Manager Encoded |
| .aef | ELECTRICAL Designer Related |
| .aeh | IPer Advanced Embedded Hypertext |
| .aem | Alphacam Wire EDM Parameter Macro |
| .aep | Adobe After Effects Project Format |
| .aepkey | Advanced Encryption Package Key Format |
| .aepx | Adobe After Effects XML Project Format |
| .aer | Adobe Atmosphere |
| .aes | AES Crypt Encrypted Format |
| .aet | Adobe After Effects Template Format |
| .aetx | Adobe After Effects Format |
| .aeu | Microsoft AutoRoute Express Europe Route |
| .aex | Greetings Card Format |
| .aexpk | PGP Armored Extracted Public Key |
| .af | 3DPlus Model |
| .af2 | Micrografx FlowCharter 2.0 Flowchart Format |
| .af3 | Micrografx FlowCharter Flowchart Format |
| .afa | Astrotite Compressed Data |
| .afb | Alphacam Flame VB Macro |
| .afc | Compressed Audio Interchange Format Format |
| .afd | Alphacam Flame Drawing Format |
| .afe | Avid Media Metadata Format |
| .aff | Advanced Forensics Format Disk Image |
| .afg | Tablet Assembly |
| .afl | XMap Related |
| .afm | Adobe Font Metrics Format |
| .afn | ArtCAM Font |
| .afo | Advanced File Organizer Catalog |
| .afo-xvid | Compressed Video |
| .afp | FileProtector Encrypted Format |
| .afploc | Apple Mac OS X Filing Protocol Location Format |
| .afpp | Mac Apple Share |
| .afr | FreeBSD |
| .afs | STAAD.foundation Project Format |
| .afs3 | AFS 3 Basic Encrypted |
| .aft | Family Tree Data Format |
| .afw | Micrografx FlowCharter Work Area |
| .afx | Auto F/X Image Format |
| .afz | Family Tree Backup |
| .ag | Applix Graphics |
| .ag4 | Microsoft Access G4 |
| .aga | ArcGIS ArcGlobe |
| .agb | Nintendo Game Boy Advance ROM Image |
| .agc | Compiled Script |
| .agd | Agile Advantage Format |
| .agd1 | Adobe FreeHand For Mac Drawing |
| .agd2 | Adobe FreeHand 7 For Mac |
| .agdb | ANSYS DesignSpace |
| .age3rec | Age Of Empires III Recorded Game |
| .age3sav | Age Of Empires III Save Game |
| .age3scn | Age Of Empires III Scenario Format |
| .age3Xrec | Age Of Empires III: The WarChiefs Recorded |
| .age3xsav | Age Of Empires III: The WarChiefs Save Game |
| .age3Xscn | Age Of Empires III: The WarChiefs Scenario |
| .age3yrec | Age Of Empires III: The Asian Dynasties Recorded Game |
| .age3ysav | Age Of Empires III: The Asian Dynasties Save Game |
| .age3Yscn | Age Of Empires III: The Asian Dynasties Scenario |
| .agent | Forte Agent And FreeAgent Data |
| .ageo | Dream Aquarium Fish Model |
| .agf | Atlas GIS Native Binary Geodataset |
| .agg | AggFlow Plant Flow Analysis |
| .aggr | Adobe Captivate Aggregator Format |
| .agi | Asterisk Gateway Interface Format |
| .agif | Active GIF Creator Project Format |
| .agilekeychain | 1Password Data |
| .agl | ArgusLab Molecular Graphics Modelling |
| .agldei | Adobe GoLive Template |
| .agls | Adobe GoLive Snippet |
| .aglsl | Adobe GoLive Site |
| .agm | Audio Format |
| .agmodule | Adobe Lightroom Module |
| .ago | Autolog Script |
| .agp | ArtGem Project Format |
| .agprefs | Adobe Photoshop Lightroom Preferences |
| .agr | Ableton Live Groove Format |
| .ags | AfterGRASP Script |
| .agtemplate | Adobe Photoshop Lightroom Preset |
| .agtoolkit | Adobe Photoshop Lightroom |
| .agv | ArcGlobe Video Metadata |
| .agw | Aspen Graphics |
| .agwl | Abstract Grid Workflow Language |
| .agx | Rational XDE |
| .agx1 | Adobe FreeHand For Mac Extension |
| .agz | AggFlow Aggregate Plant Flow Diagram |
| .ah | FreeBSD |
| .ahb | AIM High Briefcase Report |
| .ahc | Resident Evil 4 |
| .ahd | Microsoft Dynamics AX On-line Help Data Format |
| .ahf | Aces High Film |
| .ahi | Microsoft Dynamics AX Online Help Index Format |
| .ahk | AutoHotkey Script Format |
| .ahl | EMule Metadata Format |
| .ahod | Homeworld |
| .ahp | AutoCAD Help |
| .ahs | Adobe Photoshop Halftone Screens Format |
| .ahtm | HTML |
| .ahtml | HTML |
| .ahu | Adobe Photoshop Hue Saturation Lightness Format |
| .ahx | WinAHX Tracker Module Format |
| .ai | Adobe Illustrator Graphics Format |
| .ai3 | Generic Encapsulated PostScript Graphic Format |
| .ai4 | Generic Encapsulated PostScript Graphic |
| .ai5 | Generic Encapsulated PostScript Graphic |
| .ai6 | Generic Encapsulated PostScript Graphic |
| .ai65 | Adobe PageMaker For Mac Extension |
| .ai7 | Generic Encapsulated PostScript Graphic |
| .ai8 | Generic Encapsulated PostScript Graphic Format |
| .aia | Adobe Illustrator Action Format |
| .aic | Advanced Image Coding Format |
| .aid | Star Trek Armada Arficicial Intelligence Parameters |
| .aidl | AIDL Interface |
| .aif | Audio Interchange File Format Sound Format |
| .aifb | AIF Builder Project Format |
| .aifc | Audio Interchange File Format Sound File With Compression |
| .aiff | Audio Interchange File Format |
| .aifr | Audio Interchange File Format |
| .aig | Architecture Drawing |
| .aih | Attribute Index |
| .aij | Oracle After-Image Journal |
| .ail | AutoImager |
| .aim | AIMMS ASCII Model Format |
| .aimppl | AIMP Media Player Playlist Format |
| .ain | ArcView Attribute Index Format |
| .aio | Bitmap |
| .aip | Adobe Illustrator Plugin Format |
| .air | Adobe AIR Rich Internet Applications |
| .airapplication | Adobe AIR Application |
| .airi | Adobe AIR Intermediate |
| .airport | RealFlight Simulator |
| .airports | RealFlight Airports Data |
| .ais | ACDSee Album Image Sequence Format |
| .ait | Adobe Illustrator Template Format |
| .aiu | Advanced Installer Updates Configuration Format |
| .aiv | AIVault Data Format |
| .aiw | Formula One 2001 Game |
| .aix | IBM AIX |
| .aja | Backup Revision Control Archive |
| .ajb | Alphacam Water Jet VB Macro |
| .ajd | Alphacam Water Jet Drawing |
| .ajg | AJC Grep Project |
| .ajl | CA ARCserve Backup Journal |
| .ajm | Alphacam Water Jet Parameter Macro |
| .ajp | AJP Player Video Format |
| .akai | Akai S-series Floppy Disk Image |
| .akf | Adobe Acrobat Key |
| .akm | Aksharamala Keymap Binary |
| .akp | Akai S5000, S6000 Program Format |
| .aks | Aksharamala Keymap Binary |
| .akt | Aksharamala Keymap Source |
| .akw | Adobe RoboHelp Help Project Index Designer |
| .al | A-Law Compressed Sound Format |
| .al3 | Electronic Data Interchange |
| .al8 | AAA Logo Project |
| .ala | Alan Interactive Fiction Language |
| .alac | Apple Lossless Audio Codec Audio Format |
| .alarmz | Alarmz Alarm |
| .alaw | A-Law Compressed Sound Format |
| .alb | Alpha Five Data Dictionary |
| .alb3 | Adobe PageMaker Document |
| .alb4 | Adobe PageMaker For Mac Document |
| .alb5 | Adobe PageMaker 5 Document |
| .alb6 | Adobe PageMaker For Mac |
| .albm | Photo Album Format |
| .album | Thumbnail Cache |
| .alc | Visual MP3 Embedded Dynamic Lyrics |
| .alc4 | Adobe PageMaker For Mac Dictionary |
| .alco | URL Manager Pro |
| .ald | Microsoft Dynamics AX Application Label Data Format |
| .ald2 | Adobe PageMaker For Mac |
| .ald3 | Adobe PageMaker 3 For Mac |
| .ald4 | Adobe Pagemaker 4 For Mac |
| .ald5 | Adobe PageMaker 6 For Mac |
| .ald6 | Adobe PageMaker 6 For Mac |
| .aldf | Aldefaer Data |
| .ale | Avid Log File Format |
| .alf | ACT! Lookup Format |
| .alf6 | PageMaker Default |
| .alg | ER Mapper Algorithm |
| .alh5 | Adobe PageMaker Add-in |
| .ali | BlackBerry Application Loader Format |
| .alias | Alias Image |
| .aliases | LabVIEW IP Adresses Map |
| .all | Cubasis Project Format |
| .allow | Linux Access |
| .alm | Alpha Five Database Information |
| .almb | Mac OS 8.1 Action Module Data |
| .almn | Location Manager Module |
| .aln | LexNavigator Database Update |
| .alo | Star Wars: Empire At War Game |
| .alp | Ableton Live Pack Format |
| .alr | ADRIFT Language Resource Format |
| .als | Ableton Live Project Format |
| .alt | Microsoft Dynamics AX Temporary Format |
| .alt3 | Adobe PageMaker Template |
| .alt4 | Adobe PageMaker For Mac |
| .alt5 | Adobe Pagemaker 5 For Mac Document |
| .alt6 | Adobe PageMaker 6 |
| .alth | QuickHelp For Mac |
| .altp | QuickHelp |
| .altq | QuickView Settings |
| .altv | QuickView Help |
| .alv | Adobe Photoshop Levels Format |
| .alw | A-law G.711 European Telephony Format |
| .alx | BlackBerry Application Loader Format |
| .aly | Sage ACT! |
| .alz | ALZip Compressed Format |
| .am | GLPK Automake/autoconf Makefile Definitions Format |
| .am1 | Adventure Maker Project Format |
| .am2 | AutoPlay Menu Studio Ver.2 Data |
| .am3 | AutoPlay Menu Studio Ver.3 Data |
| .am4 | AutoPlay Menu Studio Version 4 Project Format |
| .am5 | AutoPlay Menu Studio Ver.5 Data Format |
| .am6 | AutoPlay Menu Studio Ver.6 Data Format |
| .am7 | AutoPlay Menu Studio Ver.7 Data Format |
| .ama | ArcGIS ArcMap |
| .amaya | Amaya |
| .amb | Alphacam 3D Mill Or 2D Mill VB Macro Format |
| .amc | Ant Movie Catalog Format |
| .amd | Alphacam 3D Mill, 2D Mill Drawing |
| .ame | ACT! E-mail System Library |
| .amf | DSMIA/Asylum Module Music Format |
| .amfm | Adobe Multiple Font Metrics Format |
| .ami | Amica Paint |
| .amipro | Ami Pro Table Structure |
| .amj | AceMoney |
| .amk | AceMoney Backup |
| .aml | Microsoft Assistance Markup Language |
| .amm | Abbyy Format |
| .amo | AIM AOL Instant Messenger UI Extension |
| .amodel | ActiveModeler Project |
| .amos | AMOS Basic Code |
| .amp | Adobe Photoshop Arbitrary Map Settings Format |
| .amr | Adaptive Multi-Rate Compressed Audio Format |
| .ams | Velvet Studio Module Format |
| .amsm | Atomic Mail Sender Project |
| .amsorm | OnLine Ringman Format |
| .amst | Atomic Mail Sender Template |
| .amt | ABBYY Finereader 5.0 Pro |
| .amt50 | BERNINA V5.0 Embroidery Software Template |
| .amt60 | BERNINA V6.0 Embroidery Software Template |
| .amu | Sony PictureGear Studio Photo Album Format |
| .amv | AMV Video File Format |
| .amw | Alcorn McBride Show Controller |
| .amx | Adobe Motion Exchange Format |
| .amxd | Max For Live Project Format |
| .amxx | AMX Mod X Plug-in Format |
| .amz | Amazon MP3 Downloader Format |
| .an | Adobe Edge Animate Project Format |
| .an1 | DeLorme Street Atlas Drawing Format |
| .an2 | Croc Animation Format |
| .an8 | Anim8or 3D Animation Format |
| .ana | Analysis For Windows |
| .anat | XNBC Network Anatomy |
| .anc | Alphacam NC Program |
| .android | Readme |
| .ane | Adobe AIR Native Extension Format |
| .anf | ANSYS DesignModeler |
| .ang | AIMSUN NG Related |
| .anh | ActivTrak Net View History |
| .ani | Animated Cursor |
| .anim | Amiga Animation Format |
| .animset | FaceFX Animation Set Format |
| .animset_ingame | FaceFX In-Game Animation Set Format |
| .aniso | Chemical Crystallography |
| .anjuta | Anjuta DevStudio Project Format |
| .anki | Anki Deck |
| .anl | Project Analyzer Saved Analysis |
| .anm | 3D Animation Format |
| .anme | Anime Studio Project Format |
| .ann | Microsoft Windows Help Annotation Format |
| .annot | Adobe Digital Editions Annotations Format |
| .anr | DeLorme Street Atlas Route |
| .ans | ANSI Text File (ANSI Art) |
| .ansr | AnswerTool Answer Document |
| .ansym | Adobe Edge Animate Library Format |
| .ant | CalcAnt Saved Calculation |
| .antifrag | DC++ Incomplete Download |
| .antispam5 | Personal AntiSpam Settings Format |
| .antmpl | Adobe Edge Animate Template |
| .anv | AirNav Image |
| .anx | HotDocs Answer Format |
| .any | AnyRail Layout Plan Format |
| .anydvdhd | AnyDVD Registration Key |
| .ao | ActionOutline Data |
| .aob | DVD Audio Object Format |
| .aod | Microsoft Dynamics AX Object Data Format |
| .aof | Artlantis Object Format |
| .aoi | AOI Scene Format |
| .aois | CFS Console Add-on Installer Settings Format |
| .aol | America On-line Related Format |
| .aom | Adobe After Effects Output Settings Format |
| .aop | JBoss AS JAR Archive |
| .aos | Archos Signed Encrypted Data Format |
| .aot | ZenWorks SnAppShot Application Binary Object Template |
| .ap | Fifth Generation Systems Active Page Format |
| .ap0 | Microsoft Windows APW_data |
| .ap2 | ActivInspire Resource Pack |
| .ap3 | Asprova Project |
| .ap? | LoseThos C+ Source |
| .apa | RSView Application Manager Archive |
| .apalbum | Apple Aperture Album Format |
| .apb | Alphacam Punch VB Macro |
| .apc | AiroPeek Wireless Trace Capture |
| .apcdoc | Ashampoo Photo Commander |
| .apd | ACDSee Photo Document |
| .apdb | Apple Aperture Library |
| .apdetected | Apple IPhoto |
| .apdisk | Apple Mac OS X Related |
| .ape | Winamp Plug-ins AVS Format |
| .ApertureEdit | Apple Aperture |
| .ApertureExport | Apple Aperture |
| .apex | AVM Sample Studio Bank |
| .apf | Adobe Acrobat Profile Format |
| .apfacename | Apple IPhoto Face Data |
| .apg | APGen Script |
| .aph | Ability Photoalbum Album Database Format |
| .api | Adobe Acrobat Plugin Format |
| .apin | Adobe InDesign Import/export Filter |
| .api_filters | Eclipse API Settings |
| .apj | AutoCAD Project |
| .apk | Google Android Package Format |
| .apl | ArcPad Layer Format |
| .aplg | Audials One Add-on Format |
| .aplibrary | Aperture Pictures Library Database Format |
| .aplmodel | Apple ICal |
| .apln | Adobe InDesign 3rd Party Extension |
| .aplp | Audials One Add-on Installation Package Format |
| .aplt | Mac OS X AppleScript Applet |
| .apm | Aldus Placeable Metafile |
| .apng | Animated Portable Network Graphics Format |
| .apnx | Amazon Kindle Index Format |
| .apo | Abacre Paperless Office |
| .app | MAC Application Package Or Core System Service Format |
| .app-se | Sony Ericsson XPERIA X10 |
| .appcache | HTML5 Cache Manifest |
| .appdata | VMWare Cache |
| .appdownload | Mac OS X App Store Incomplete Download Format |
| .appicon | VMWare Cache |
| .apple | Apple AppleSingle Data |
| .appledouble | Apple AppleDouble Resource |
| .applescript | AppleScript Script Format |
| .AppleSyncInfo | IOS |
| .applet | Eclipse IDE For Java Developers Format |
| .appletviewer | Java Appletviewer |
| .apple_partition_map | Apple Partition Scheme |
| .application | ClickOnce Deployment Manifest Format |
| .appref-ms | Application Reference Format |
| .appup | Erlang Application Upgrade Format |
| .appv | App-V Archive |
| .appx | Microsoft AppX Application Package Format |
| .appxmanifest | Windows Store App Source Manifest |
| .appxsym | Microsoft Visual Studio Windows 8 Application Information Format |
| .appxupload | Microsoft Visual Studio Windows 8 Application Upload Format |
| .apr | ArcView Project Format |
| .apref-ms | Application Reference |
| .aprj | ApacheConf Project |
| .aps | Microsoft Visual C++ Binary Version Of Resource Format |
| .apsmartalbum | Apple Aperture |
| .apt | Almost Plain Text Format |
| .apu | Audacity Audio |
| .apv | Acerose Password |
| .apvault | Apple Aperture Vault |
| .apw | Password |
| .apx | Borland C++ Appexpert Database Format |
| .apxl | Apple Keynote Presentation XML Document Settings Format |
| .apxt | DataLink Setting |
| .apz | AMS Shared Project Format |
| .ap_ | Google Android Development Resources Package Format |
| .aq | Ancestral Quest Genealogy |
| .aq1 | AptiQuiz Test |
| .aqa | AptiQuiz Result |
| .aqc | AquaChem Database |
| .aqf | Aquifer-Generated Web Page |
| .aql | AOL DLL |
| .aqm | AlpineQuest GPS Hiking Map Format |
| .aqp | Quizmaker 08 And Older Quiz |
| .aqq | AQQ Extension |
| .aqt | AQTitle Subtitles Format |
| .aqz | Amateur Radio Questionary Data |
| .ar | Linux/Unix Command Library Format |
| .ar-wmp | BrainVoyager QX Anatomical-resolution Volume Map |
| .ara | Archivaldo Resource Archive |
| .arb | Alphacam Router VB Macro |
| .arbvp1 | Google Earth Shader |
| .arc | ARC Lossless Data Compression And Archive Format |
| .arch00 | F.E.A.R. Game Archive Format |
| .arch01 | F.E.A.R. 2 Game |
| .archcfg | F.E.A.R. 2 Project Origin Configuration |
| .architect | Soundweb London Design |
| .archiver | Incredible Bee Archiver Archive |
| .arcinfo | ArcInfo Info |
| .arcut | Adobe Prelude Rough Cut Format |
| .ard | ArtiosCAD Workspace Format |
| .are | BioWare Aurora Engine Area |
| .arena | Quake 3 Id Tech 3 Game Engine Arena Settings Format |
| .arf | WebEx Advanced Recording Format |
| .arff | Weka Attribute-relation Format |
| .arg | AutoCAD Profile Export Format |
| .argo | ArgoUML Project |
| .arh | El Airplane Game Archive Format |
| .ari | ARRI Raw Image Format |
| .aria | Chipsounds Audio Format |
| .ariax | Chipsounds XML Sound Format |
| .arj | ARJ Compressed Archive Format |
| .ark | ARC File Archiver CPM/Port Archive Format |
| .arl | AOL Organizer Format |
| .arlc | Commandos 2 Men Of Courage Game |
| .arm | MySQL Archive Storage Engine Metadata |
| .ArmA2OAProfile | ArmA 2 Settings |
| .ArmA2Profile | ARMA2 Profile |
| .armx | ASP.NET Source |
| .army | Impossible Creatures Collection Of Created Creatures |
| .arn | Astronomical Research Network Image Format |
| .aro | SteelArrow Script Format |
| .arp | Alphacam Router Post Format |
| .arpack | ArtRage Package |
| .arpi | Adobe Extension |
| .arq | BSM Action Request System Client Macro |
| .arr | Advanced RAR Password Recovery Project Format |
| .ars | Adobe After Effects Render Settings Format |
| .arsc | Google Android Resource Format |
| .arscript | ArtRage Script |
| .art | Bernina Artista Embroidery Format |
| .art42 | V1.x Explorations Projects |
| .art50 | BERNINA V5.0 Embroidery Software Designs |
| .art6 | Articulate Presenter Compressed |
| .ART60 | BERNINA V6.0 Embroidery Software Designs |
| .artb | Artboard Vector Drawing Format |
| .artf | Adobe FreeHand Xtra |
| .artproj | Artifacts Project Format |
| .artwork | ArtStudio Image Format |
| .artx | Artisteer Project |
| .artz | Adobe Illustrator For Mac |
| .aru | Autorun.aru Malicious |
| .arv | Microsoft Autoroute User Information |
| .arw | Sony Digital Camera RAW Image Format |
| .arx | AutoCAD Runtime Extension Format |
| .arxml | AUTOSAR XML |
| .ary | SmartStart Scripting Toolkit |
| .arz | MySQL Archive Storage Engine Data |
| .as | Adobe Flash ActionScript Document |
| .as$ | Microsoft Word Temporary |
| .as2 | ACTIVstudio Resource |
| .as2proj | FlashDevelop Project Format |
| .as3a | ActivInspire Resource |
| .as3proj | FlashDevelop ActionScript 3 Project Format |
| .as4 | AskSam Backup Format |
| .as4a | ActivInspire Resource Pack |
| .as? | LoseThos Assembly Source |
| .asa | Active Server Configuration Format |
| .asat | Assemble SAT 3D Model Format |
| .asax | ASP.NET Application Optional Source Format |
| .asb | Alphacam Stone VB Macro Format |
| .asbx | Microsoft ASP.Net BridgeHandler |
| .asc | ASCII Text Characters Format |
| .ascii | ASCII Text Characters Format |
| .ascm | Adobe Content Server Message |
| .ascs | Adobe Device Central Format |
| .ascx | Active Server Pages Web User Control Format |
| .asd | Microsoft Word Auto-save Document Format |
| .asdb | Asphyre Sphinx Archive |
| .asdvdcrtproj | Aimersoft DVD Creator Project |
| .ase | Adobe Swatch Exchange Format |
| .asec | Google Android Encrypted Application Package Format |
| .asef | Adobe Swatch Exchange |
| .asep | Separator For Mac |
| .asf | Advanced Systems (streaming) Format |
| .asg | Airport Tycoon Saved Game |
| .asgp | HP-UX NIS Maps Configuration |
| .ash | Audiosurf Audio Metadata Format |
| .ashbak | Ashampoo Burning Studio Backup Archive Format |
| .ashdisc | Ashampoo Disk Image Format |
| .ashlang | Ashampoo Media Player+ |
| .ashprj | Ashampoo Burning Studio Project Format |
| .ashx | ASP.NET Web Handler Format |
| .asi | Alpha Five Storage Format |
| .asic | ASIC Source |
| .asis | Apache As Is |
| .ask | AskSam Database Format |
| .asl | Adobe Photoshop Layer Style Format |
| .asm | Assembler Source Code Format |
| .asmdot | SolidWorks Assembly Template |
| .asmprp | SolidWorks Assembly Custom Properties Tab Template |
| .asmx | Active Server Plus Web Services Source Format |
| .asn | GameSpy Arcade Skin |
| .asnd | Adobe Soundbooth Sound Document Format |
| .aso | Sage Accpac Simply ASO Import |
| .asp | Active Server Page Script Page |
| .asp+ | ASP.NET ASP+ |
| .aspr | ASProtect Related |
| .asproj | Microsoft Visual Studio Analysis Services Project |
| .aspx | Active Server Page Extended ASP.NET Script Format |
| .asr | Adobe Photoshop Scratch Area Format |
| .asrp | Arc Standard Raster Product |
| .ass | Advanced SubStation Alpha Subtitle Format |
| .asset | Unity Asset Format |
| .assistant | HP Printer Utility For Mac Assistant Plugin |
| .assoc | Associate This Association Database |
| .asstrm | Splinter Cell Blacklist Game Data |
| .ast | Adobe Photoshop Colour Separation Table |
| .ast2 | Astrotite |
| .astx | Adobe Story Exported Script |
| .asu | ToolBook Package Definition |
| .asv | Adobe Photoshop Selective Colour Format |
| .asvf | Asphyre Sphinx Archive |
| .asw | ACDSee Slideshow Wizard Format |
| .aswcs | Avast! Antivirus Skin |
| .asws | Avast! Antivirus Skin |
| .asx | Microsoft Advanced Streaming Redirector Format |
| .asxml | XML Music Playlist |
| .asy | LTspice IV Circuit Diagram Format |
| .asz | LoseThos Assembly Source |
| .as_ | Winhelp Compressed |
| .at3 | Airport Tycoon 3 Saved Game |
| .at5 | Lowrance Chart Format |
| .at65 | Adobe PageMaker For Mac |
| .ata | Antenna Project |
| .atahd | Puppy Linux ATA Hard Drive Flag Format |
| .atak | Soundscape Audio-Take |
| .atb | AnetHelp Tools |
| .atc | AutoCAD Catalog Format |
| .atd | Microsoft Systems Management Server |
| .ate | Microsoft Office Accounting Compressed Backup Format |
| .atf | Adobe Photoshop Transfer Function Format |
| .ath | Alphacam Lathe Thread Format |
| .atheme | Amazing Clock Theme |
| .ati | Microsoft Office Accounting Updated Company Format |
| .atk | Andrew Toolkit Raster Object |
| .atl | Artlantis 3D Scene Format |
| .atlas | Stronghold 3 Editor |
| .atlg | SlimBrowser Auto Login |
| .atloc | Apple Mac OS X Finder |
| .atm | Vue 3D Environment Format |
| .atmc | Adobe Type Manager |
| .atmn | Automation Anywhere Macro |
| .atmsphr | TerraGen Latmoshpere Andscape Render |
| .atn | Adobe Photoshop Actions Settings Format |
| .ato | ATO Modeler Project |
| .atom | Atom Web Feed Format |
| .atoms | Ribbons Atoms |
| .atp | Alphacam Lathe Post |
| .atpz | Automise Compressed Project |
| .atr | Atari 8-bit Disk Image |
| .atrac | Sony ATRAC Audio Format |
| .ats | Advanced ETL Processor Transformation Script Format |
| .att | Web Form Data Format |
| .attr | Apple IPhoto Image Attributes |
| .attx | Cadence Atribut |
| .atv | ACT! |
| .atx | Animation Master Plugin Format |
| .aty | Association Type Placeholder |
| .atz | Aston Compiled Theme |
| .atz3 | Automise |
| .au | Unix Audio Sound File Format |
| .au3 | AutoIt V3 Script Format |
| .au? | LoseThos Autofile |
| .auc | AUC Database |
| .aud | Westwood Studios Audio Format |
| .audiblePrefs | Audible Preference |
| .audionote | AudioNote |
| .auf | Alphacam User Font |
| .aug | Red Hat Linux Shellvars |
| .aui | AGE3D UI Editor Color Table |
| .aum | Adobe Update Manager Data |
| .aup | Audacity Project Format |
| .aupreset | Apple Logic Studio Preset |
| .aur | AutoREALM Map |
| .aurx | AutoREALM Project |
| .aus | AutoREALM Symbols |
| .aut | AutoIt Pre V3 Script Format |
| .auth | ShopSite Store Authorization |
| .autoconf | Autoconfiguration |
| .automaticdestinations-ms | Microsoft Windows 7 Jump List Format |
| .autoplay | AutoPlay Media Studio Project Format |
| .autoreg | Mozilla Application Suite Auto Registration Clue |
| .aux | TeX/LaTeX Auxiliary References Format |
| .auz | Ableton Authorization Format |
| .av | Final Draft AV Document |
| .ava | AvaaBook EBook |
| .avastconfig | Avast Configuration |
| .avastlic | Avast! License Format |
| .avastsounds | Avast! Soundpack Format |
| .avatar | Google Talk Avatar Format |
| .avb | Avid Binary Image Format |
| .avc | MPEG-4 AVC Advanced Video Coding Movie Format |
| .avchd | High Definition Video Format |
| .avd | MAGIX Movie Edit Pro Video Data Format |
| .ave | Avid User Format |
| .avenirproj | StoryMill Project Format |
| .avery | Avery Design & Print Online Label Format |
| .avf | Video Information |
| .avg | AVG Antivirus Virus Database |
| .avgdx | AVG Diagnostic Format |
| .avhd | Microsoft Hyper-V Differencing Disk Format |
| .avi | Audio Video Interleave Movie Format |
| .avj | Avira Anti-Vir Job Format |
| .avl | ArcView Legend Template Format |
| .avm | AVG Incremental Persistent |
| .avn | AltaVENTE Application User Notes |
| .avp | Avid Project Format |
| .avr | Audio Visual Research Sound Format |
| .avs | Stardent AVS X Bitmap Image Format |
| .avsi | Avisynth Script |
| .avst | VirtualDub Template |
| .avt | Savy Soda Avatar For IPhone Avatar |
| .avv | Avid Media Composer Volume Bin Format |
| .avw | AnalyzeAVW Image |
| .avx | ArcView Extension Plugin Format |
| .avz | AviSys Backup |
| .aw | Answer Wizard Format |
| .awa | ActiveWords |
| .awb | Adaptive Multi-rate Wideband ACELP Codec Audio Format |
| .awbs | Data Storage |
| .awc | Emulex AWC Firmware Update Format |
| .awcav | ActiveWorlds Browser User Avatar Format |
| .awd | Microsoft Fax Document |
| .awdb | Microsoft Works For Mac Database Format |
| .awe | Adobe Acrobat Bookmark XML |
| .awf | Adobe WorkFlow Workgroup Plugin |
| .awg | Activeworlds Object Group Format |
| .awh | ActiveWorlds Browser Help |
| .awi | AIM Widget Package |
| .awk | AWK Programming Language Script Format |
| .awkw | Awkwords Word Generator Format |
| .awl | Ad-Aware Language |
| .awlive | Active WebCam Live Capture Format |
| .awm | Likno AllWebMenus Format |
| .awp | Ability Write Document Template Format |
| .awr | Ad-Aware Reference |
| .aws | Ability Spreadsheet Spredsheet Format |
| .awshortcut | ActiveWords Shortcut |
| .awss | Microsoft Works For Mac Spreadsheet |
| .awt | AbiWord Template Document Format |
| .aww | Ability Write Document Format |
| .awwp | Microsoft Works For Mac Document |
| .awx | Microsoft DirectX |
| .awzip | ActiveWords Compressed Solution |
| .ax | DirectShow Filter Format |
| .ax3 | Apex Sketch |
| .axa | Annodex Digital Media Format |
| .axd | ASP.NET Web Handler Format |
| .axe | Microsoft Autoroute Map Format |
| .axf | ARM Executable Format |
| .axg | Microsoft AutoRoute Trip |
| .axl | XML Project |
| .axm | Axmedis Object |
| .axp | CDBurnerXP Audio Compilation Format |
| .axq | Edit Rocket Ada Editor |
| .axr | ElcomSoft Adcanced Archive Password Recovery |
| .axs | ActiveX Script |
| .axt | Adobe Photoshop Replace Color Range Format |
| .axv | Annodex Digital Media Format |
| .axw | Analyzer StateForms |
| .axx | AxCryot Encrypted Format |
| .ay | Project Format |
| .az | WinDVD Related |
| .az! | Vuze Partial Download Format |
| .aza | QazaR Archive Compressed |
| .azd | Amazon Software Download |
| .azf | Secure Format |
| .azp | Close Combat Effect |
| .azs | Secure Format |
| .azw | Amazon Kindle EBook Format |
| .azw1 | Amazon Kindle Topaz E-book Format |
| .azw2 | Amazon Kindle Program Format |
| .azw3 | Amazon Kindle EBook Format |
| .azw3f | Amazon Kindle Metadata |
| .azw3r | Amazon Kindle Metadata |
| .azw4 | Amazon Kindle Print Replica Ebook Format |
| .azz | AZZ Cardfile Information Card Format |
| .azzx | Uncompressed AZZ Cardfile Data 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.
