| ABK | - | Corel Draw AutoBackup |
| ACL | - | Corel Draw 6 keyboard accelerator |
| ACM | - | Used by Windows in the system directory |
| ACP | - | Microsoft Office Assistant Preview file |
| ACT | - | Microsoft Office Assistant Actor file |
| ACV | - | OS/2 drivers that compress and decompress audio data |
| AD | - | After Dark screensaver |
| ADB | - | Appointment database used by HP 100LX organizer |
| ADD | - | OS/2 adapter drivers used in the boot process |
| ADM | - | After Dark MultiModule screensaver |
| ADP | - | Used by FaxWorks to do setup for fax modem interaction |
| ADR | - | After Dark Randomizer screensaver |
| AFM | - | Adobe font metrics |
| AF2 | - | ABC Flowchart file |
| AF3 | - | ABC Flowchart file |
| AI | - | Adobe Illustrator drawing |
| AIF | - | Apple Mac AIFF sound |
| ALB | - | JASC Image Commander album |
| ALL | - | Arts & Letters Library |
| AMS | - | Velvert Studio music module (MOD) file |
| ANC | - | Canon Computer Pattern Maker file that is a selectable list of pattern colors |
| ANI | - | Animated Cursor |
| ANS | - | ANSI text |
| API | - | Application Program Interface file; used by Adobe Acrobat |
| APR | - | Lotus Approach 97 file |
| APS | - | Microsoft Visual C++ file |
| ARC | - | LH ARC (old version) compressed archive |
| ARJ | - | Robert Jung ARJ compressed archive |
| ART | - | Xara Studio drawing |
| ART | - | Canon Crayola art file |
| ASA | - | Microsoft Visual InterDev file |
| ASC | - | ASCII text |
| ASD | - | WinWord AutoSave |
| ASM | - | Assembler language source file |
| ASP | - | Active Server Page (an HTML file containing a Microsoft server-processed script) |
| ASP | - | Procomm Plus setup and connection script |
| AST | - | Claris Works "assistant" file |
| ATT | - | AT&T Group 4 bitmap |
| AVI | - | Microsoft Video for Windows movie |
| AWD | - | FaxView document |
|
| BAK | - | Backup file |
| BAS | - | BASIC code |
| BAT | - | Batch file |
| BFC | - | Windows 95 Briefcase document |
| BG | - | Backgammon for Windows game |
| BI | - | Binary file |
| BIF | - | GroupWise initialization file |
| BIN | - | Binary file |
| BK | - | Sometimes used to denote backup versions |
| BK$ | - | Also sometimes used to denote backup versions |
| BKS | - | An IBM BookManager Read bookshelf |
| BMK | - | An A bookmark file |
| BMP | - | Windows or OS/2 bitmap |
| BM1 | - | Apogee BioMenace data file |
| BRX | - | A file for browsing an index of multimedia options |
| BSP | - | Quake map |
| BS1 | - | Apogee Blake Stone data file |
| BTM | - | Batch file used by Norton Utilities |
| B4 | - | Helix Nuts and Bolts file |
|
| C | - | C code |
| CAB | - | Microsoft cabinet file (program files compressed for software distribution) |
| CAL | - | CALS Compressed Bitmap |
| CAL | - | Calendar schedule data |
| CAS | - | Comma-delimited ASCII file |
| CAT | - | IntelliCharge categorization file used by Quicken |
| CB | - | Microsoft clean boot file |
| CCB | - | Visual Basic Animated Button configuration |
| CCF | - | Multimedia Viewer configuration file used in OS/2 |
| CCH | - | Corel Chart |
| CCM | - | Lotus CC:Mail "box" (for example, INBOX.CCM) |
| CDA | - | CD Audio Track |
| CDF | - | Microsoft Channel Definition Format file |
| CDI | - | Phillips Compact Disk Interactive format |
| CDR | - | Core Draw drawing |
| CDT | - | Corel Draw template |
| CDX | - | Corel Draw compressed drawing |
| CEL | - | CIMFast Event Language file |
| CFB | - | Comptons Multimedia file |
| CFG | - | Configuration file |
| CGI | - | Common Gateway Interface script file |
| CGM | - | Computer Graphics Metafile |
| CH | - | OS/2 configuration file |
| CHK | - | File fragments saved by Windows Disk Defragmenter or ScanDisk |
| CHP | - | Ventura Publisher chapter |
| CIL | - | Clip Gallery download package |
| CIM | - | Sim City 200 file |
| CIN | - | OS/2 change control file that tracks changes to an INI file |
| CK1 | - | iD/Apogee Commander Keen 1 data file |
| CK2 | - | iD/Apogee Commander Keen 2 data file |
| CK3 | - | iD/Apogee Commander Keen 3 data file |
| CK4 | - | iD/Apogee Commander Keen 4 data file |
| CK5 | - | iD/Apogee Commander Keen 5 data file |
| CK6 | - | iD/Apogee Commander Keen 6 data file |
| CLASS | - | Java class |
| CLP | - | Windows Clipboard file |
| CLS | - | Visual Basic Class Module |
| CMD | - | Command file for Windows NT (similar to a DOS .BAT file) |
| CMD | - | DOS CP/M command file |
| CMD | - | dBase-II program file |
| CMF | - | Corel Metafile |
| CMP | - | JPEG Bitmap |
| CMP | - | Address document |
| CMV | - | Corel Move animation |
| CMX | - | Corel Presentation Exchange image |
| CNF | - | Configuration file used by Telnet, Windows, and other applications |
| CNM | - | Windows application menu options and setup file |
| CNQ | - | Compuworks Design Shop file |
| CNT | - | Windows (or other) system content files for the help index and other purposes |
| COB | - | trueSpace2 object |
| COD | - | Microsoft C compiler output as displayable assembler with original C as comments |
| COM | - | Command file (program) |
| CPD | - | Fax Cover document |
| CPE | - | Fax Cover document |
| CPI | - | Microsoft MS-DOS code page information file |
| CPL | - | Control Panel extension |
| CPL | - | Corel colour palette |
| CPP | - | C++ code |
| CPR | - | Corel Presents Presentation |
| CPT | - | Corel Photo-Paint image |
| CPX | - | Corel Presentation Exchange Compressed drawing |
| CRD | - | Cardfile file |
| CRP | - | Corel Presents Run-Time Presentation |
| CRT | - | Certificate file |
| CSC | - | Corel Script |
| CSP | - | PC Emcee On-Screen image |
| CSV | - | Comma-separated values file |
| CT | - | Scitex CT Bitmap |
| CTL | - | Used in general to mean a file containing control information. |
| CUE | - | Microsoft Cue Cards data |
| CUR | - | Windows Cursor |
| CUT | - | Dr Halo bitmap |
| CV | - | Corel Versions archive |
| CV | - | Microsoft CodeView information screen |
| CWK | - | Claris Works data file |
| CWS | - | Claris Works template |
| CXX | - | C++ source code file |
|
| DAT | - | Data file |
| DAT | - | WordPerfect Merge Data |
| DBF | - | Aston-Tate dBASE database |
| DBX | - | DataBeam image |
| DCR | - | Shockwave file |
| DCS | - | Desktop Color Separation file |
| DCX | - | Fax image (based on PCX) |
| DDF | - | BTRIEVE database |
| DEF | - | SmartWare II data file |
| DEF | - | C++ Definition |
| DER | - | Certificate file |
| DIB | - | Device-Independent Bitmap |
| DIC | - | Dictionary |
| DIF | - | Data Interchange Format spreadsheet |
| DIR | - | Macromedia Director file |
| DIZ | - | Description file |
| DLG | - | C++ Dialogue Script |
| DLL | - | Dynamic-Link Library |
| DMF | - | X-Trakker music module (MOD) file |
| DOC | - | FrameMaker or FrameBuilder document |
| DOC | - | WordStar document |
| DOC | - | WordPerfect document |
| DOC | - | Microsoft Word document |
| DOT | - | Microsoft Word document Template |
| DPR | - | Borland Delphi project header file |
| DRV | - | Driver |
| DRW | - | Micrografx Designer/Draw |
| DSG | - | DooM saved game |
| DSM | - | Dynamic Studio music module (MOD) file |
| DSP | - | Microsoft Developer Studio project |
| DSQ | - | Corel QUERY file |
| DSW | - | Microsoft Developer Studio workspace |
| DWG | - | AutoCAD drawing eXchange format |
| DXF | - | AutoDesk Drawing Interchange format |
|
| EMF | - | Enhanced Windows Metafile |
| ENC | - | Encore file |
| EPS | - | Encapsulated PostScript image |
| ER1 | - | ERWin file |
| ERX | - | ERWin file |
| EVY | - | Envoy document |
| EWL | - | Microsoft Encarta document |
| EXE | - | Executable file (program) |
|
| F | - | FORTRAN file |
| F77 | - | FORTRAN file |
| F90 | - | FORTRAN file |
| FAR | - | Farandole Composer music module (MOD) file |
| FAV | - | Microsoft Outlook navigation bar |
| FAX | - | FAX Type image |
| FH3 | - | Aldus Freehand 3 drawing |
| FIF | - | Fractal image file |
| FITS | - | CCD camera image |
| FLC | - | AutoDesk FLIC animation |
| FLI | - | AutoDesk FLIC animation |
| FLT | - | Corel filter |
| FLT | - | StarTrekker music module (MOD) file |
| FMB | - | Oracle binary source code for form, version 4.0 and later |
| FMT | - | Oracle text format of form, version 4.0 and later |
| FMT | - | Microsoft Schedule+ print file |
| FMX | - | Oracle executable form, version 4.0 and later |
| FOG | - | Fontographer font |
| FON | - | System font |
| FOR | - | FORTRAN file |
| FOT | - | Font-related file |
| FP | - | FileMaker Pro file |
| FP1 | - | Flying Pigs for Windows data file |
| FP3 | - | FileMaker Pro file |
| FPX | - | FlashPix bitmap |
| FRM | - | Form |
| FRM | - | FrameMaker or FrameBuilder document |
| FRM | - | Oracle executable form version 3.0 and earlier |
| FRM | - | Visual Basic form |
| FRM | - | WordPerfect Merge form |
| FRX | - | Visual Basic form stash file |
|
| GAL | - | Corel Multimedia Manager album |
| GCP | - | Ground Control Point file used in image processing of remote sensing data . |
| GED | - | Graphic Environment Document (drawing) |
| GEM | - | GEM metafile |
| GEN | - | Ventura-Generated text file |
| GFC | - | Patton&Patton Flowcharting 4 flowchart file |
| GFI | - | Genigraphics Graphics Link presentation |
| GFX | - | Genigraphics Graphics Link presentation |
| GID | - | Windows 95 global index file (containing help status) |
| GIF | - | CompuServe bitmap |
| GIM | - | Genigraphics Graphics Link presentation |
| GIX | - | Genigraphics Graphics Link presentation |
| GNA | - | Genigraphics Graphics Link presentation |
| GNX | - | Genigraphics Graphics Link presentation |
| GRA | - | Microsoft Graph |
| GRD | - | Grid file, used in image processing of remote sensing data often to form map projections. |
| GRP | - | Program Manager Group |
| GTK | - | Graoumftracker (old) music module (MOD) file |
| GT2 | - | Graoumftracker (new) music module (MOD) file |
| GWX | - | Genigraphics Graphics Link presentation |
| GWZ | - | Genigraphics Graphics Link presentation |
| GZ | - | Unix Gzip compressed file |
|
| H | - | C program header |
| HED | - | HighEdit document |
| HEL | - | Microsoft Hellbender saved game |
| HEX | - | Macintosh BinHex 2.0 file |
| HGL | - | HP Graphics Language drawing |
| HLP | - | Help file |
| HOG | - | Lucas Arts Dark Forces WAD file |
| HPJ | - | Visual Basic Help Project |
| HPP | - | C++ program header |
| HQX | - | Macintosh BinHex 4.0 file |
| HST | - | History file |
| HT | - | HyperTerminal |
| HTM | - | Hypertext document |
| HTML | - | Hypertext document |
| HTX | - | Extended HTML template |
|
| ICA | - | Citrix file |
| ICB | - | Targa bitmap |
| ICM | - | Image Color Matching profile file |
| ICO | - | Windows Icon |
| IDD | - | MIDI Instrument Definition |
| IDQ | - | Internet Data Query file |
| IFF | - | Amiga ILBM |
| IGF | - | Inset Systems metafile |
| IIF | - | QuickBooks for Windows interchange file |
| IMA | - | WinImage file |
| IMG | - | GEM image |
| INC | - | Assembler language or Active Server include file |
| INF | - | Information file |
| INI | - | Initialization file |
| INP | - | Oracle source code for form, version 3.0 and earlier |
| INS | - | InstallShield install script |
| INS | - | X-Internet sign-up file |
| ISO | - | Lists the files on a CD-ROM; based on the ISO 9660 CD-ROM file system standard |
| ISP | - | X-Internet sign-up file |
| ISU | - | InstallShield uninstall script |
| IT | - | Impulse Tracker music module (MOD) file |
| IW | - | Idlewild screensaver |
|
| JAR | - | Java ARchive file (a compressed file for applets and related files) |
| JAVA | - | Java source code |
| JBF | - | Paint Shop Pro image browser file |
| JFF | - | JPEG bitmap |
| JIF | - | JPEG bitmap |
| JMP | - | SAS JMPDiscovery chart-to-statistics file |
| JN1 | - | Epic MegaGames Jill of the Jungle data file |
| JPEG | - | JPEG bitmap |
| JPG | - | JPEG bitmap |
| JS | - | JavaScript source code |
| JTF | - | JPEG bitmap |
|
| KDC | - | Kodak Photo-Enhancer |
| KFX | - | KoFax Group 4 image |
| KYE | - | Kye game data |
|
| LBM | - | Deluxe Paint bitmap |
| LDB | - | Microsoft Access lock file |
| LEG | - | Legacy document |
| LHA | - | Alternate file suffix for LZH |
| LIB | - | Library |
| LIS | - | Output file produced by a Structured Query Reporting (SQR) program |
| LOG | - | Log file |
| LPD | - | Helix Nuts and Bolts file |
| LRC | - | Intel Video Phone file |
| LST | - | List file |
| LWO | - | Lightwave Object file |
| LWP | - | Lotus Wordpro 96/97 file |
| LZH | - | LH ARC compressed archive |
| LZS | - | Skyroads data file |
|
| M3D | - | Corel Motion 3D animation |
| MAC | - | MacPaint image |
| MAD | - | Microsoft Access module |
| MAF | - | Microsoft Access Form |
| MAK | - | Visual Basic or MS Visual C++ Project |
| MAM | - | Microsoft Access Macro |
| MAP | - | Map file |
| MAP | - | Duke Nukem 3D WAD game file |
| MAQ | - | Microsoft Access Query |
| MAR | - | Microsoft Access Report |
| MAS | - | Lotus Freelance Graphics Smartmaster file |
| MAT | - | Microsoft Access Table |
| MAX | - | Paperport file |
| MAZ | - | Hover maze data |
| MB1 | - | Apogee Monster Bash data file |
| MCC | - | Dialer10 calling card |
| MCS | - | MathCAD image |
| MCW | - | Microsoft Word for Macintosh document |
| MDA | - | Microsoft Access add-in |
| MDB | - | Microsoft Access database |
| MDE | - | Microsoft Access MDE file |
| MDL | - | Digital Tracker music module (MOD) file |
| MDL | - | Quake model file |
| MDN | - | Microsoft Access blank database template |
| MDW | - | Microsoft Access Workgroup |
| MDZ | - | Microsoft Access wizard template |
| MED | - | Music Editor, OctaMED music module (MOD) file |
| MER | - | Format for interchanging spreadsheet/database data; recognized by Filemaker, Excel, and others |
| MET | - | Presentation Manager metafile |
| MI | - | Miscellaneous |
| MIC | - | Microsoft Image Composer file |
| MID | - | MIDI music |
| MMF | - | Microsoft Mail File |
| MMM | - | Microsoft Multimedia Movie |
| MOD | - | FastTracker, StarTrekker, Noise Tracker (etc.) music module file |
| MOD | - | Microsoft Multiplan spreadsheet |
| MOV | - | QuickTime for Windows movie |
| MPE | - | MPEG animation |
| MPEG | - | MPEG animation |
| MPG | - | MPEG animation |
| MPP | - | Microsoft Project file |
| MPP | - | CAD drawing file format |
| MP3 | - | MPEG Audio Layer 3 (AC3) file |
| MSG | - | Microsoft Mail message |
| MSN | - | Microsoft Network document |
| MSP | - | Microsoft Paint bitmap |
| MTM | - | MultiTracker music module (MOD) file |
| MUS | - | Music |
| MVB | - | Microsoft Multimedia Viewer file |
| MWP | - | Lotus Wordpro 97 Smartmaster file |
|
| NAP | - | NAP Metafile |
| NCB | - | Microsoft Developer Studio file |
| NSF | - | Lotus Notes database |
| NST | - | Noise Tracker music module (MOD) file |
| NTF | - | Lotus Notes database template |
|
| OBD | - | Microsoft Office binder template |
| OBD | - | Microsoft Office Binder |
| OBJ | - | Object file |
| OBZ | - | Microsoft Office Binder Wizard |
| OCX | - | Microsoft Object Linking and Embedding custom control |
| OFN | - | Microsoft Office FileNew file |
| OFT | - | Microsoft Outlook template |
| OKT | - | Oktalyzer music module (MOD) file |
| OLB | - | OLE Object Library |
| OLE | - | OLE object |
| OPT | - | Microsoft Developer Studio file |
| ORG | - | Lotus Organiser file |
| OR2 | - | Lotus Organiser 2 file |
| OR3 | - | Lotus Organiser 97 file |
|
| P10 | - | Tektronix Plot 10 drawing |
| PAB | - | Microsoft Personal Address Book |
| PAK | - | Quake WAD file |
| PAL | - | Windows colour palette |
| PAT | - | Corel Draw pattern |
| PBK | - | Microsoft Phonebook |
| PBM | - | Portable Bitmap |
| PCD | - | Kodak Photo-CD image |
| PCL | - | HP Laserjet bitmap |
| PCS | - | PICS animation |
| PCT | - | Macintosh PICT drawing |
| PCX | - | ZSoft PC Paintbrush bitmap |
| PDF | - | Adobe Acrobat Portable Document Format or Netware Printer Definition File |
| PDF | - | Package Definition File from Microsoft Systems Management Server |
| PDQ | - | Patton&Patton Flowcharting PDQ Lite file |
| PFA | - | Type 1 font (ASCII) |
| PFB | - | Type 1 font (binary) |
| PFC | - | PF Component |
| PFM | - | Printer Font Metrics |
| PGL | - | HP Plotter drawing |
| PGM | - | Portable Graymap (bitmap) |
| PIC | - | PC Paint bitmap |
| PIC | - | Lotus picture |
| PIC | - | Macintosh PICT drawing |
| PIF | - | Program Information File |
| PIF | - | IBM PIF drawing |
| PIG | - | Lucas Arts Dark Forces WAD file |
| PIN | - | Epic Pinball data file |
| PIN | - | Epic Pinball data file |
| PIX | - | Inset Systems bitmap |
| PJ | - | MKS Source Integrity file |
| PKG | - | Microsoft Developer Studio application extension (similar to a DLL file) |
| PL | - | Perl program |
| PLT | - | HPGL Plotter drawing |
| PLT | - | AutoCAD Plot drawing |
| PM5 | - | Pagemaker 5.0 file |
| PM6 | - | Pagemaker 6.0 file |
| P65 | - | Pagemaker 6.5 file |
| PNG | - | Portable Network Graphics bitmap |
| PNG | - | Paint Shop Pro Browser catalogue |
| PNT | - | MacPaint graphic file |
| POT | - | Microsoft PowerPoint Template |
| PP4 | - | Picture Publisher 4 bitmap |
| PPA | - | Microsoft PowerPoint Add-in |
| PPM | - | Portable Pixelmap bitmap |
| PPS | - | Microsoft PowerPoint slide show |
| PPT | - | Microsoft PowerPoint presentation |
| PRE | - | Lotus Freelance presentation |
| PRF | - | Windows system file |
| PRN | - | Print Table (space delimited text) |
| PRS | - | Harvard Graphics for Windows presentation |
| PRZ | - | Lotus Freelance Graphics 97 file |
| PS | - | Postscript Interpreted drawing |
| PSD | - | Adobe Photoshop bitmap |
| PST | - | Microsoft Outlook Personal Folder File |
| PTM | - | Polytracker music module (MOD) file |
| PUB | - | Ventura Publisher publication |
| PUB | - | Microsoft Publisher document |
| PWD | - | Microsoft Pocket Word document |
| PWZ | - | Microsoft PowerPoint Wizard |
| PXL | - | Microsoft Pocket Excel spreadsheet |
|
| QAD | - | PF QuickArt Document |
| QBW | - | QuickBooks for Windows file |
| QDT | - | Quick Books data file from the Quicken UK Accountancy/Tax/Invoice program |
| QLB | - | Quick Library |
| QRY | - | Microsoft Query |
| QT | - | QuickTime Movie |
| QTM | - | QuickTime Movie |
| QXD | - | Quark XPress file |
|
| R | - | Pegasus Mail resource file |
| RA | - | Real Audio sound |
| RAM | - | Real Audio sound |
| RAS | - | Sun Raster Images bitmap |
| RAW | - | Raw File Format (bitmap) |
| RC | - | Microsoft Visual C++ Resource Script |
| REC | - | Recorder macro |
| REG | - | Registration file |
| RES | - | Microsoft Visual C++ Resource |
| RFT | - | RFT-DCA |
| RLE | - | Run-Length Encoded bitmap |
| RM | - | Real Audio video file |
| RMI | - | MIDI music |
| ROV | - | Rescue Rover data file |
| RPT | - | Microsoft Visual Basic Crystal Reports file |
| RTF | - | Rich Text Format document |
| RTM | - | Real Tracker music module (MOD) file |
|
| SAM | - | Ami Professional document |
| SAV | - | Saved game file |
| SCC | - | Microsoft Source Safe file |
| SCD | - | Matrix/Imapro SCODL slide image |
| SCD | - | Microsoft Schedule+ 7 |
| SCH | - | Microsoft Schedule+ 1 |
| SCN | - | trueSpace2 scene |
| SCP | - | Dial-Up Networking Script |
| SCR | - | Windows screensaver |
| SCR | - | Fax image |
| SCT | - | Scitex CT bitmap |
| SC2 | - | Microsoft Schedule+ 7 |
| SDL | - | SmartDraw library |
| SDR | - | SmartDraw drawing |
| SDT | - | SmartDraw template |
| SEA | - | Self-expanding archive (used by Stuffit for Mac files and possibly by others) |
| SEP | - | Tagged Image File Format (TIFF) bitmap |
| SHB | - | Corel Show presentation |
| SHB | - | Document shortcut file |
| SHG | - | Hotspot bitmap |
| SHS | - | Shell scrap file |
| SHW | - | Corel Show presentation |
| SIT | - | Stuffit archive of Mac files |
| SLK | - | Symbolic Link (SYLK) spreadsheet |
| SND | - | NeXT sound |
| SND | - | Mac Sound Resource |
| SQC | - | Structured Query Language (SQR) common code file |
| SQR | - | Structured Query Language (SQR) program file |
| STM | - | Scream Tracker music module (MOD) file |
| STY | - | Ventura Publisher style sheet |
| SVX | - | Amiga 8SVX sound |
| SYS | - | System file |
| S3M | - | Scream Tracker 3 music module (MOD) file |
|
| TAR | - | Tape Archive |
| TAZ | - | Unix Gzip/Tape Archive |
| TEX | - | Texture file |
| TGA | - | Targa bitmap |
| TGZ | - | Unix Gzip/Tape Archive |
| THEME | - | Windows 95 Desktop Theme |
| THN | - | Graphics Workshop for Windows thumbnail |
| TIF | - | Tag Image File Format (TIFF) bitmap |
| TIFF | - | Tag Image File Format (TIFF) bitmap |
| TIG | - | Tiger file, used by US government to distribute maps |
| TLB | - | OLE Type Library |
| TMP | - | Windows temporary file |
| TRM | - | Terminal file |
| TRN | - | MKS Source Integrity project usage log |
| TTF | - | TrueType font |
| TWF | - | TabWorks file |
| TWW | - | Tagwrite Template |
| TX8 | - | MS-DOS Text |
| TXT | - | Text |
| T2T | - | Sonata CAD modelling software file |
|
| UDF | - | Windows NT Uniqueness Database File |
| ULT | - | Ultratracker music module (MOD) file |
| URL | - | Internet shortcut |
| USE | - | MKS Source Integrity file |
|
| VBP | - | Visual Basic Project |
| VBW | - | Microsoft Visual Basic workspace |
| VBX | - | Visual Basic custom control |
| VCF | - | Vevi Configuration File; defines objects for use with Sense8's WorldToolKit |
| VDA | - | Targa bitmap |
| VI | - | Virtual Instrument file from National Instruments LABView product |
| VLB | - | Corel Ventura Library |
| VOC | - | Creative Labs Sound Blaster sound |
| VP | - | Ventura Publisher publication |
| VSD | - | Visio drawing (flow chart or schematic) |
| VST | - | Targa bitmap |
| VSW | - | Visio Workspace file |
| VXD | - | Microsoft Windows virtual device driver |
|
| WAD | - | Large file for Doom game containing video, player level, and other information |
| WAV | - | Windows Waveform sound |
| WB1 | - | QuattroPro for Windows spreadsheet |
| WB2 | - | QuattroPro for Windows spreadsheet |
| WBK | - | Microsoft Word Backup |
| WBL | - | Argo WebLoad II upload file |
| WCM | - | WordPerfect Macro |
| WDB | - | Microsoft Works database |
| WEB | - | CorelXara Web document |
| WGP | - | Wild Board Games data file |
| WID | - | Ventura width table |
| WIL | - | WinImage file |
| WIZ | - | Microsoft Word Wizard |
| WK1 | - | Lotus 123 versions 1 & 2 spreadsheet |
| WK3 | - | Lotus 123 version 3 spreadsheet |
| WK4 | - | Lotus 123 version 4 spreadsheet |
| WKS | - | Lotus 123 Worksheet spreadsheet |
| WKS | - | Microsoft Works document |
| WLF | - | Argo WebLoad I upload file |
| WLL | - | Microsoft Word Add-In |
| WMF | - | Windows Metafile |
| WOW | - | Grave Composer music module (MOD) file |
| WP | - | WordPerfect document |
| WPW | - | Novel PerfectWorks document |
| WP4 | - | WordPerfect 4 document |
| WP5 | - | WordPerfect 5 document |
| WP6 | - | WordPerfect 6 document |
| WPD | - | WordPerfect Demo |
| WPD | - | WordPerfect Document |
| WPG | - | WordPerfect Graphic |
| WPS | - | Microsoft Works document |
| WPT | - | WordPerfect Template |
| WQ1 | - | QuattroPro/DOS spreadsheet |
| WQ2 | - | QuattroPro/DOS version 5 spreadsheet |
| WRI | - | Write document |
| WRL | - | Virtual Reality model |
| WS1 | - | WordStar for Windows 1 document |
| WS2 | - | WordStar for Windows 2 document |
| WS3 | - | WordStar for Windows 3 document |
| WS4 | - | WordStar for Windows 4 document |
| WS5 | - | WordStar for Windows 5 document |
| WS6 | - | WordStar for Windows 6 document |
| WS7 | - | WordStar for Windows 7 document |
| WSD | - | WordStar 2000 document |
| WVL | - | Wavelet Compressed Bitmap |
|
| XAR | - | Corel Xara drawing |
| XLA | - | Microsoft Excel add-in |
| XLB | - | Microsoft Excel toolbar |
| XLC | - | Microsoft Excel chart |
| XLD | - | Microsoft Excel dialogue |
| XLK | - | Microsoft Excel backup |
| XLM | - | Microsoft Excel macro |
| XLS | - | Microsoft Excel worksheet |
| XLT | - | Microsoft Excel template |
| XLV | - | Microsoft Excel VBA module |
| XLW | - | Microsoft Excel workbook / workspace |
| XM | - | FastTracker 2, Digital Tracker music module (MOD) file |
| XR1 | - | Epic MegaGames Xargon data file |
| XTP | - | XTree data file |
| XY3 | - | XYWrite III document |
| XY4 | - | XYWrite IV document |
| XYP | - | XYWrite III Plus document |
| XYW | - | XYWrite for Windows 4.0 document |
|
| YAL | - | Arts & Letters clipart library |
| YBK | - | Microsoft Encarta Yearbook |
|
| Z | - | Unix Gzip |
| ZIP | - | Zip file |
| ZOO | - | An early compressed file format |
|
000-
999 | - | Used to number old versions of files and number related data files |
| 12M | - | Lotus 123 97 Smartmaster file |
| 123 | - | Lotus 123 97 file |
2GR,
3GR | - | VGA Graphics driver/configuration files under Windows |
| 386 | - | A file for use in an 80386 or higher microprocessor |
| 669 | - | Composer 669, Unis Composer music mod file |
|
#01
and higher | - | A method of numbering picture files for a roll of film that has been scanned |
| $$$ | - | Used by OS/2 to keep track of archived files |
| @@@ | - | Screen files used in the installation and instruction on use of applications |
