What Is a Filename Extension?

The file extension (also known as the file extension) is a mechanism used by the operating system to mark file types. Generally, an extension follows the main file name and is separated by a delimiter. An extension can be thought of as a type of metadata. ^[1]

File extension (Filename Extension, or extension file name , suffix ) is early

Practical application

Description

Open \ edit

I. Documents

Only when

Learning Object Code Library File

Xi: The source code of the Chinese version of the C language " Xi "

Object code library file

Interface: Chinese version of the C language source interface source code

A object code library file

AAUAAuto programming language source code file

APROJ Quick Hand (AAuto Programming Language) Project File

AAM Authorware shocked file

AAS Authorware shocked package

ABF Adobe Binary Screen Font

ABK CorelDRAW Auto Backup File

ABS This type of file is sometimes used to indicate an abstract (just like an abstract or synopsis in a scientific article, taken from abstract)

ACCDB Access2007 database file

ACE Ace Compressed File Format

ACL CorelDRAW 6 keyboard shortcut file

ACMWindows system directory file

ACP Microsoft Office Assistant Preview File

ACR American University of Radiation Medicine file format

ACT Microsoft office assistant file

ACV OS / 2 driver for compressing or decompressing audio data

AD After Dark screen saver

ADA Ada source file (non-GNAT)

ADB Ada source file body (GNAT); HP100LX organizer's contract database

ADD OS / 2 adapter driver for boot process

ADF Amiga Disk File

ADI AutoCAD Device Independent Binary Plotter Format

ADM After Dark multi-module screen saver; Windows NT policy template

ADP FaxWork Interactive installation file for fax modem; Astound Dynamite file

ADR After Dark random screen saver; Smart Address's address book

ADS Ada Source File Specification (GNAT)

AEP Adobe After Effects Project File

AFM Adobe Font Scale

FlowChat files for AF2, AF3 ABC

AI Adobe Illustrator format graphics

AIF, AIFF Audio Interchange File, Sound Format for Silicon Graphic and Macintosh Applications

AIFC compressed AIF

AIM AOL Instant Messaging

AIS ACDSee Graphics Sequence File; Velvet Studio Device File

AKW RoboHELP help project all A-keywords

ALAW European Phone Audio Format

ALB JASC Image Commander Photo Album

ALL Art and Letters Library

AMS Velvet Studio music module (MOD) file; Extreme Tracker module file

ANC Canon Computer's palette file containing a series of optional color palettes

Animated cursor in ANI Windows

ANS ANSI text file

Game files saved in ANT SimAnt For Windows

API Application Design Interface file used by Adobe Acrobat

APK Android Apps

APR Lotus Approach 97 file

APSMicrosoft Visual C ++ file

ARC LH ARC Compressed Archive File

ARI Aristotle sound file

ARJ Robert Jung ARJ compressed file

ART Xara Studio painting files; Canon Crayola art files; Clip Art file format; another ray tracing format; AOL's marker files compressed with Johnson-Grace compression algorithm

ASA Microsoft Visual InterDev file

ASC ASC text file; PGP algorithm encrypted file

ASD Microsoft Word auto-save file; Microsoft advanced streaming FORMat (ASF) description file; Velvet Studio example file can be opened with NSREX

ASE Velvet Studio Sample File

ASF Microsoft Advanced Streaming Format File

ASM assembly language source files, Pro / E assembly files

ASO Astound Dynamite Object File

ASP dynamic webpage file; ProComm Plus installation and connection script file; Astound introduction file

AST Astound multimedia file; ClarisWorks "assistant" file

ASV DataCAD saves files automatically

ASX Cheyenne backup script file; Microsoft Advanced Streaming Redirector file, video file

ATT AT <Group 4 bitmap file

ATW Any Time Deluxe For Windows Personal Information Manager File from Personal Software

AU Sun / NeXT / DEC / UNIX sound files; audio U-Law (pronounced "mu-law") file format

AVB Computer Associates Inoculan Anti-Virus Virus Infected File

AVI Microsoft Audio Video Interleave movie format

AVR Audio Visual Research file format

AVS application visualization format

AWD FaxVien Document

AWR Telsis Digital Storage Audio File Extension Format

Axx ARJ compressed sub-package serial number file, used to compress a large file into several small compressed packages

A3L Authorware 3.x library file

A4L Authorware 4.x library file

A5L Authorware 5.x library file

A3M, A4M Authorware Macintosh Unpacked Files

A4P Authorware Package File without Runtime

A3W, A4W, A5W Unpackaged Authorware Windows Files

B object code library file

BAK backup file

BAS BASIC Module File

BAT batch file

BDF West Point Bridger Designer file

BFC Windows 95 Briefcase Document

BG Backgammon For Windows Game Files

BGL Microsoft Flight Simulator

BI binary

BIF Group Wise initialization file

BIFF XLIFE 3D format file

BIN binary file

BK is sometimes used to represent backup versions

BKS IBM BookManager Read Bookshelf File

BMK bookmark file

BMP Windows or OS / 2 bitmap file

BMI Apogee BioMenace data file

BOOK Adobe FrameMaker Book file

BOX Lotus Notes mailbox file

BPL Borlard Delph 4 Packaging Library

BQY BrioQuery file

BRX for viewing files in a multimedia object directory

BSC MS Developer Studio Browser Information File

BSP Quake Graphics File

BS1 Apogee Blake Stone Data File

BS_ Microsoft Bookshelf Find menu shell extension

BT Bluff Titler 3D Text Animation Tool Project File

Batch files used by the BTM Norton application

BUD Quicken backup disk

BUN CakeWalk sound bundle file (a MIDI program)

BW SGI black and white image file

BWV Commercial Wave File

BYU BYU movie file format

B4 Helix Nuts and Bolts file

C object code library file

CC code file

C0l Typhoon Wave File

CAB Microsoft Compressed Archive File

Drafix CAD files for CAD Softdek

CAL CALS compressed bitmap; calendar schedule data

CAM Casio camera format

CAP compressed music file format

CAS comma separated ASC file

IntellCharge classification file used by CAT Quicken

CB Microsoft Clean Boot File

CBI binary volume format file (for IBM mainframe systems)

CC Visual dBASE user-defined class file

CCA cc: mail file

CCB Visual Basic Dynamic Button Configuration File

CCF multimedia viewer profile for OS / 2

CCH Corel chart file

CCM Lotus cc: mailbox (e.g. "INBOX.CCM")

CCO CyberChat Data File

CCT Macromedia Director Shockwave Projection

CDA CD audio track

CDF Microsoft Channel Definition Format File

CDI Philip's high-density disk interactive format

CDM Visual dBASE Custom Data Module File

CDR CorelDRAW drawing file; raw audio CD data file

CDT CorelDRAW template

CDX CorelDRAW compressed drawing file; Microsoft Visual FoxPro index file

CEL CIMFast event language file

CER certificate file (MIME x-x509-ca-cert)

CFB Compton Multimedia File

CFG configuration file

CFM CotdFusion template file; Visual dBASE Windows user-defined form

CFR CF Media File

CGI public gateway interface script file

CGM computer graphics metafile

CH OS / 2 configuration file

CHK File fragmentation saved by Windows Disk Defragmenter or ScanDisk

CHM compiled HTML file

CHR character set (font file)

CHP Ventura Publisher Chapter File

CHT ChartViem file; Harvard Graphics vector file

CIF Adaptec CD Creator CD image file

CIL Clip Gallery download package

CIM SimCity 2000 file

CIN OS / 2 change control file for tracking changes in INI files

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 file

CLL Crick Software Clicker file

CLP Windows Clipboard File

CLS Visual Basic Class File

CMD Windows NT, OS / 2 command file; DOS CD / M command file; dBASE program file

CMF Corel Metafile

Game files saved by CMG Chessmaster

CMP JPEG bitmap file; address file

CMV Corel Move Animation File

CMX Corel Presentation Exchange image

CNF Telnet, Windows and other configuration files used by applications whose format changes

CNMWindows application menu options and installation files

CNQ Compuworks Design Shop file

CNT Windows (or other) system used to help index or other purpose content files

COB TrueSpace 2 Object File

COD Microsoft C compiler displayable machine code / assembly code file with source C code as a comment

COM command file (program)

CPD Corel Print Office file (graphics)

CPD, CPE Fax Coverage Document

CPI MicrosoftMS-DOS code page information file

CPL Control Panel Extension, Corel Color Plate

CPO Corel print storage file

CPP C ++ code file

CPR Corel provides instruction file

CPT Corel Photos-Painting Images

CPX Corel Presentation Exchange

CRD Windows Cardfile

CRP Corel runtime introduction file; Visual dBASE custom report file

CRT Certification Document

CSC Corel script file

CSP PC Emcee On_Screen image

CSS waterfall table file

CST Macromedia Director Cast file

CSV comma-separated value file

CT Scitex CT bitmap file; Paint Shop Pro Grapic editor file

CTL is usually used to represent a file containing control information; it is used by FaxWork to hold information about each fax received or sent

CUE Microsoft Prompt Data File

CUR Windows cursor file

CUT Dr Halo bitmap file

CV Corel version archive; Microsoft CodeView info screen file

CWK ClarisWorks data file.

CWS ClarisWorks Module

CXT Macromedia Director protected (non-editable) projection file

CXX C ++ source code files

D Object Code Library File

DAT data files; WrodPerfect merged data files; for some MPEG format files

DB Borland's Paradox 7 table

DBC Microsoft VisualFoxPro Database Container File

DBF dBASE files, a format created by Ashton-Tate, can be ACT! , Lipper, FoxPro, Arago, Wordtech, Xbase, and similar database or database related product identification; available data files (can be opened by Excel 97); Oracle 8.1.x table space files

DBX DataBearn image; Microsoft Visual FoxPro form file

DCM DCM module format file

DCR shock wave file

DCS Desktop Color Delimited File

DCT Microsoft Visual FoxPro Database Container

DCU Delphi compilation unit file

DCX Microsoft Visual FoxPro database container; PCX-based fax image; macro

DC5 DataCAD drawing file

DDF Btrieve or Xtrieve data definition file, which contains metadata used to describe the Btrieve or Xtrieve file

DDIF Digital Equipment or Compaq format for saving their image and word processing documents

DEF SmartWare data file; C ++ module definition file

DEFI Oracle 7 uninstall script file

DEM file used to represent the USGS datum of the digital height model

DER certification

DEWF Macintosh Sound Cap / Sound Edit recording device format

Model files in the Grand Theft Auto series developed by DFF ROCKSTAR GAMES

DGN Macintosh 95 CAD Drawing File

DIB device independent bitmap

DIC Catalog

DIF data interchangeable spreadsheet

DIG DigiLink format; Sound Designer audio file

DIR MacromediaDirector file

DIZ description file

DLG C ++ dialog script file

DLL dynamic link library

DLS downloadable sound files

DMD Visual dBASE Data Module File

DMF X-Trakker Music Module (MOD) File

DOC FrameMaker or FrameBuilder document; Word Star document, Word Perfect document, Microsoft Word2003 document; DisplayWrite document

DOCX Microsoft Word 2007 document

DOT Microsoft Word document template

DPL Borland Delph3 compression library

DPR Borland Delphi Engineering Header

DRAW Acorn object-based vector image file

DRV driver

DRW Micrografx Designer / Draw; Pro / E drawing file

DSF Micrografx Designer VFX file

File saved by DSG DOOM

DSM Dynamic Studio Music Module (MOD) File

DSP Microsoft Developer Studio project file

DSQ Corel QUERY (Query) File

DST Embroidery Machine Graphic File

DSW Microsoft Developer Studio workspace file

STARS data file for DTA Word Bank (World Bank)

DTD SGML Document Type Definition (DTD) file

DTED ground height digital data (graphical data format) file

DTF Symantec Q & A related database data files

DTM DigiTrakker Module File

DUN Microsoft dial-up network export file

DV Digital Video File (MIME)

DWD DiamondWare Digitized File

DWG AutoCAD drawing file; AutoCAD or Generic CADD old version drawing format

DXF interchangeable drawing file format, binary DWG format text representation; data exchange file

DXRMacromedia Director protected (non-editable) movie file

D64 Commodore 64-bit Analog Disk Image File

E object code library file

E easy language source code file

EC Easy Language Module

EDA Ensoniq ASR Disk Image

EDB Easy Language Database

EDD element definition document (FrameMaker + SGML document)

EDE Ensoniq EPS disk image

EDK Ensoniq KT Disk Image

EDQ Ensoniq SQ1 / SQ2 / Ks32 Disk Image

EDS Ensoniq SQ80 Disk Image

EDV Ensoniq VFX-SD Disk Image

EFA Ensoniq ASR file

EFE Ensoniq EPS file

EFK Ensoniq KT file

EFQ Ensoniq SQ1 / SQ2 / Ks32 file

EFS Ensoniq SQ80 file

EFV Ensoniq VFX-SD file

EMD ABT Expansion Module

EMF Windows Enhanced Metafile

EML Microsoft Outlook Express Mail Message (MIME RTC822) File

ENC Playback File

ENFF Neutral File Format Extension

EPHTML Perl explains enhanced HTML files

EPS compressed PostScript image

EPSF Compressed PostScript File

ERIERWin file

ERR File used to store error messages when RobooHELP help compiler attempts to compile a help system source file

EPXERWin file

ESPS ESPS audio file

EUI Ensoniq ESP Family Compact Disk Image

EVY Envoy Document

EWL Microsoft Encarta Document

EXC Microsoft Word Forbidden Word Dictionary

EXE executable file (program)

F object code library file

F FORTRAN file

F2R Farandoyle linear module format

F3R Farandoyle Block Linear Module Format

F77 FORTRAN file

F90 FORTRAN file

FAR Fradole Composer Music Module (MOD) file

FAV Microsoft Outlook Navigation Bar

FAX fax type image

FBK Navison Financial Backup

FCD Virtual CD-ROM

FDB Navison Financial Database

FDF Adobe Acrobat Form Document File

FEM CADRE finite element network file

FFA, FFL, FFO, FFK Microsoft Quick Find File

FFF GUS PnP Bank File Format

FFT final format text (part of IBM's DCA)

FH3 Aldus Freehand 3 Drawing File

FIF Fractal image file

File format used by FIG REND386 / AVRIL

FITSCCD camera image; flexible image transmission system

FLA Macromedia Flash Movie

FLC Autodesk FLIC Animation File

Format produced by FLF Corel Paradox: Navison Financials license file; OS / 2 driver file

PLI Autodesk FLIC Animation

FLT StarTrekker music module (MOD) file; file format used by MultiGen Inc's Open Flight; Corel filter file

FM Adobe FrameMaker Document

FMB Binary source code file for Oracle version 4.0 or later forms

FML file mirror list (GetRight)

FMT Oracle 4.0 or later text format; Microsoft Schedule + print file

FMX Oracle version 4.0 or later executable forms

FND Microsoft Explorer Search File (Find applet)

FNG font set file (Font Navigator, Font Navigator)

FNK Funk Tracker module format

FOG Fontographer module font

FON system font

FOR FORTRAN file

FOT font related files

FP FileMaker Pro file

FP1 Flying Pigs for Windows data file

FP3 FileMaker Pro file

FPT FileMaker Pro file; Microsoft Fox Pro note font file

FPX FlashPix bitmap

FRM forms; Frame Maker or Frame Builder documents; Oracle executable forms (version 3.0 or earlier); Visual Basic forms; WordPerfect Merge forms; DataCAD logo report files

FRT Microsoft FoxPro report file

FRX Visual Basic form text; Microsoft FoxPro report file

FSF fPrint Audit Tool file format

FSL Borland's Paradox 7 forms; Corel Paradox saved forms

FSM Parandoyle sample format

FT Lotus Notes full text index

FTG full text search group file, generated by Windows help system to find-can be deleted and rebuilt when needed

FTS full text search citation file, generated by Windows help system when finding

FW2 Framework file

FW3 Framework file

FW4 Framework File

FXP source files compiled by Microsoft FoxPro

FZB Casio FZ-1 bank dump

FZF Casio FZ-1 Full Dump

FZV Casio FZ-1 sound dump

G object code library file

G721 Raw CCITT G.721 $ bit ADPCM format data

G723 Raw CCITT G.723 3 or 5bit ADPCM format data

GAL Corel Multimedia Manager Photo Gallery

GBA GameBoyAdvance game files

GB GameBoy game files

GBC GameBoyColor (Colour) game file

GCD Generic CADD drawing file (subsequent version)

GCP Ground Control Point (GCP) files are used to form the image data from the perspective data, and are often used to generate graphics projectsthese are used by the CHIPS (copenhagenimage processing system)

GDB InterBase Database File

GDM Ringtone, Whistle, and Soundboard Module Format

GED GEDCOM pedigree data file, a popular format for recording and exchanging pedigree data; graphic environment document drawing

GEM GEM metafile

Text files generated by GEN Ventura

GetRight GetRight Unfinished Download File

GFC Patton & Patton FlowCharting 4 flowchart file

GFI, GFX Genigraphics graphic link presentation file

GHO Norton clone disk image

GID Windows 95 global index file (including help status)

GIF CompuServe bitmap file

GIM, GIX Genigraphics graphics link presentation file

GKH Ensoniq EPS Family Cluster Disk Image File

GKS Gravis Grip Key Document

GL animation format

GNA Genigraphics graphic link presentation file

GNT generated code, executable code in Micro Focus attribute format

GNX Genigraphics graphics link presentation file

GRA Microsoft Graph file

GRD is a format file used to generate maps for remote scene data. It is usually used to form map projectsCHIPS (copenhagenimage processing system) uses these files.

GRF Grapher (Golden Software) graph file

GRP Program Management Group

GSM Raw GSM 6.10 audio stream; Raw "byte aligned" GSM 6.10 audio stream; US Robotics voice modem

GSP geometry sketchpad (The Geometer's Sketchpad & reg, general mathematics and physics teaching environment) file

GTJ GTJ2018 file

GTK Graoumftracker (old) Music Module (MOD) file

GT2 Graoumftracker (new) Music Module (MOD) file

GWX, GWZ Cenigraphis graphic link presentation file

GZ UNIX gzip compressed file

H object code library file

HC program header file

HCM IBM HCM configuration file

HCOM sound tool HCOM format

HCR IBM HCD / HCM Product Configuration File

HDF Advanced Computer Application Local Center (NCSA) geospatial Hierarchial data format file

HED HighEdit Document

Game files saved in HEL Microsoft Hellbender format

HEX Macintosh BinHex 2.0 file

HGL HP Graphics Language Drawing File

HH mapping files, including some topic IDs and mapping numbers of topics in the help file systemallows running applications to send users the appropriate context help topic HLP help files; Date CAD Windows help files

Dark Forces WAD file by HOG Lucas Arts

HPJ Visual Basic Help Engineering

HPP C ++ program header files

HPX is a Macintosh binary file that has been converted to ASCII text and can be transmitted over the Internet.

HQX Macintosh BinHex 4.0 file

HST history file

HT HyperTerminal

HTM, HTML Hypertext Document

HTT Microsoft Hypertext Template

HTX Extended HTML Template

HXM Descent2 HAM file extension

I object code library file

ICA Citrix file

ICB Targa bitmap file

ICC Kodak Printer Format File

ICL Icon Library File

ICM graphic color matching profile

ICNS Macintosh icon

ICO Windows icon

IDB MSDev Middle Tier File

IDD MIDI device definition

IDF MIDI device definition (files required by Windows 95)

IDQ Internet Data Query File

IDX Microsoft FoxPro related database index file; Symantec Q & A related database index file; Microsoft Outlook Express file

IFF interchange format file; Amiga ILBM

IGES Initial Graphics Exchange Documentation

IGF insert system metafile

IIF QuickBooks for Windows Exchange File

ILBM bitmap graphic file

IMA WinImage Disk Image File

IMG GEM image

IMZ WinImage compressed disk image file

INC assembly language or dynamic server include files

INF information file

INI initialization file; "nwsynth.ini" GMS installation of MWave DSP Synth; Cravis Ultrasound bank installation

INP Oracle version 3.0 or earlier form source code

INRS INRS telecommunications audio

INS InstallShield installation script; X-Internet signature file; Ensoniq EPS cluster equipment; Cell / MAC / PC sampling equipment

INT intermediate code, when a source program is compiled after a syntax check to generate an executable code

IOF Findit documentation

IPA Apple App

IQY Microsoft Internet Query File

ISO lists files on CD-ROM according to ISD 9660 standard for CD-ROM file system

ISP X-Internet Signature Document

IST Digital Tracking Device File

ISU InstallShield uninstall script

ISZ compressed ISO file

IT Pulse Tracking System Music Module (MOD) File

ITI Pulse Tracking System Equipment

ITS Pulse Tracking System Sampling, Internet Document Location

File formats used in IV Open Inventor

IVD more than 20/20 microdata dimension or variable grade file

IVP user profile over 20/20

IVT more than 20/20 table or collection data files

IVX more than 20/20 microdata catalog files

IW Idlewild screen saver

IWC Install Watch document

J Object Code Library File

J62 Ricoh Camera Format

JAR Java archive (a compressed file for applets and related files)

JAVA Java source files

JBF Paint Shop Pro image browsing file

JFF, JFIF, JIF JPEG files

JMPDiscovery Form Statistics File for JMP SAS

Jill of the Jungle data file for JN1 Epic MegaGames

JPE, JPEG, JPG JPEG graphics files

JS javascript source file

JSP HTML page with a reference to a Java servlet

JTF JPEG bitmap file

JSON is a lightweight data exchange format.

K object code library file

K25 Kurzweil 2500 Sample File

KAR KaraokeMIDI file (text + MIDI)

KDC Kodak light booster

KEY DataCAD icon toolbar file

KFX KoFak Group 4 image file

KIZ Kodak Digital Postcard File

KKW RoboHELP helps the engineering index designer to start with all keywords that have nothing to do with K

KMP Korg Trinity KeyMap file

KQP Konica Camera Local File

KR1 Kurzweil 2000 Sampling (Multiple Floppy Drive) File

KRZ Kurzweil 2000 Sample File

KSF Korg Trinity Sample File

KSH K + Shell

KYE Kye game data

L object code library file

LAB Visual dBASE tag file

LBM Deluxe Paint bitmap file

LBT, LBX Microsoft FoxPro label file

LDB Microsoft Access Lock File

LDF Microsoft SQL Server transaction log file

LDL Corel Paradox distribution library

LEG Legacy documentation

LES Logitech entertainment system game configuration file (same as REC file)

LFT 3D Studio (DOS) Stakeout File

Logo file for LGO Paintbrush (Microsoft Paint Application)

LHA LZH Replace File Suffix

LI LIS file encryption system encrypts files

LIA Sticker Photo Gallery File

LIB library file

LIN DataCAD linear file

Output file from LIS Structured Query Report (SQR) program

LLX Laplink Exchange Agent

LNK Windows Shortcut File

LOG log file

LPD Helix Nut and Bolt files

LRC Intel Video Phone File

Library files saved by LSL Corel Paradox

LSP AutoLISP, CommonLISP, and other LISP language files

LST list file

LU ThoughtWing library unit file

LVL Parallax Software's Miner Descent / D2 Level Extension

LWLO Lightwave layered object file

LWOB Lightwave Object File

LWP Lotus WordPro 96/97 file

LWSC Lightwave View File

LYR DataCAD layer file

LZH LH ARC Compressed File

LZS Skyroads data file

M object code library file

M1V MPEG related files (MIME "mpeg" type)

M3D Corel Motion 3D animation file

MDF Microsoft SQL Server Master Database File

MEI Motion Entis Image

MDB Microsoft Access application

MIDI Electronic Music File

MIO MIO file

MRC JNFLS "Monday Song" lyrics file

MSD virtual CD-ROM file suffix name, CD image file name

MP3 music files

MP4 video file

N Object Code Library File

N Nuke Randomic Life Generator

N1 Nuke Randomic Life Generator

N1E OM2 OMALI NENA Encrypted Document Version 1

N2E OM2 OMALI NENA Encrypted Document Version 2

N2P Net2Phone File

N3 Notation 3 Document

N3D2 The Nebula Device 2 Mesh Resource File in ASCII Format (RadonLabs GmbH)

N3E OM2 OMALI NENA Encrypted Document Version 3

N4E OM2 OMALI NENA Encrypted Document Version 4

N64 MiMiX Emulator

N64 Nintento 64 Emulation ROM Image

NA NoAdware Data File

NA2 Netscape Communicator Address Book

NAB Netscape Communicator Address Book

NAB Novell Groupwise Address Book

NAD Noder File

NAF Compressed Archive

NAI WinINSTALL File

NAK Audio

NAL ArrayScribe (NimbleGen Systems Inc.)

NAM Office Name File

NAMEONCLIPBOARD NAMEONCLIPBOARD Powertoy File

NAN Nanoscope File

NAP Electrical Network Analysis and Planification

NAP EnerGraphics VideoShow File

NAP NAP Metafile Vector Image

NAP Napster Music Security Definition File

NAP VideoShow / EnerGraphics NAPLPS Vector Image Metafile

NAP ePolicy Orchestrator Network Associates Package (Policy File) (Network Associates Technology, Inc.)

NAPLPS North American Presentation Layer Protocol Syntax = Vector image

NAR Nikon Capture Advanced RAW File (Nikon Inc.)

NAS NASTRAN File

NASB TheWord & Bible Companion New American Standard Bible

NAV Application Extension (Microsoft)

NAV Microsoft Network Component (Microsoft)

NAV MSN Application Extension

NAVCounter-Strike: Source CSBot Navigation Mesh (Valve Corporation)

NB Mathematica Notebook (Wolfram Research, Inc.)

NB Nota Bene Document File (Nota Bene Associates, Inc.)

NB WordPerfect Notebook (Corel Corporation)

NB7 NovaBACKUP System Configuration File (NovaStor Corporation)

NBA NBA Game Data

NBA Nota Bene Configuration Information File (Nota Bene Associates, Inc.)

NBATTRS NetBeans Project Attributes File

NBE Nessus File

NBF Backup NOW! Backup Archive (NewTech Infosystems)

NBG NBG Clean Registry File

NBI BackItUp Document (Ahead Software)

NBK i-Brarian

NBK NovaBACKUP Script (NovaStor Corporation)

NBK Nick-O-Matic Design Factory Project (Riverdeep Interactive Learning Limited)

NBM NetBeans Module (Sun)

NC Graphics File

NC Mastercam NC Programs (CNC Software, Inc.)

NC neatComponents

NC Numerical Control Machine Instructions

NC Preprosessed GOC Source

NC UnidatanetCDFGraphics

NC Geopath Machine Part File (SolutionWare Corporation)

NC X-editor Program for CNC Machines (X-net ApS)

O object code library file

O Object File

O UNIX / GCC Object File

O Origin C Compiled Program File (OriginLab)

O Free Pascal Object FIle for Linux or DOS Version (FPC Development Team)

O $$ Output File

O $$ Sprint Outfile

O01 Typhoon Voice File

O1 Free Pascal Object File for GO321v1 Platform (FPC Development Team)

O2C Objects to See 3D File Format (mb Software AG)

O3 Ozone Messenger Program Support Files

O8O Mediator5 Repositorytabs Vorlagen.006 File

OAB Outlook Address Book (Microsoft)

OAF ETH Oberon Applet File

OAF Outrage Animation Rows

OAF Flight Simulator Texture File (Microsoft)

OAZ NetFax Manager OAZ Fax File

OB IMB LinkWay Object File

OB ABF Outlook Backup Backup File (ABF software, Inc.)

OB $ Compressed OBJ (Microsoft)

OB1 OzWin CompuServeE-mail / Forum Access Saved Outbox File

OBA Timespace X100 Digital Video Recorder Video File (Electronics Services Agency)

OCA OLE Custom Control Library Information

OCA Visual Basic Control Typelib Cache

OCBOrigin Precompiled Origin C File (OriginLab Corporation)

OCC DB / TextWorks Database Terms and Words

OCC OptControlCentre Model File

OCD OCAD Digitized Map (Steinegger Software)

OCE Brio Query (Hyperion Solutions Corporation)

OCF Object Craft File

OCF OM2Cipher File

OCM AOL Advertising Control File (America Online, Inc.)

OCM Internet Odyssey 2 Update

OCM Netscape Communicator Aim File

OCP Advanced Art Studio

OCP Offline Commander Project File

OCR FAXGrapper FAX Text File

OCS eDoc DigiSign Digitally Signed Document (Fujitsu Denmark)

OCT Octalizer Musical File

OCT Radiance Octree Format

OCX Object Linking and Embedding (OLE) Control Extension (Microsoft)

OC_ Doko Compressed Install File

OD1 Omnis5 Database File

OD2 Omnis5 Database File

OD3 Omnis5 Database File

OD4 Omnis5 Database File

OD5 Omnis5 Database File

OD6 Omnis5 Database File

OD7 Omnis5 Database File

OD8 Omnis5 Database File

OD9 Omnis5 Database File

ODA CALS Group IV Type 2 Raster Image

ODA ODA Document

ODA Used with OCX

ODA AIBO Audio Voice (Sony)

ODB ArcView Object Database ASCII File (ESRI)

ODB Psion Organiser Datafile and LZ Diary File (Psion PLC)

ODB OpenOffice / StarOffice OpenDocument (Ver 2) Database (Sun Microsystems, Inc.)

ODB ABAQUS File (ABAQUS, Inc.)

ODB Organizers Database (ODB) Database (Organizers' Collaborative)

ODC Office Data Connection

ODC OpenOffice / StarOffice OpenDocument (Ver 2) Chart (Sun Microsystems, Inc.)

ODCCUBEFILE Office Data Connection

ODCDATABASEFILE Office Data Connection

ODCNEWFILE Office Data Connection

ODCTABLEFILE Office Data Connection

ODE Office Object Data Embedding File (Microsoft)

ODF BattleZone Cartographers Guild File

ODF OnkoS Data (OnkoS)

ODF Open Document Interchange (ODIF)

ODF Star Trek Armada Ship / Structure Infomation

ODF OpenOffice / StarOffice OpenDocument (Ver 2) Formula (Sun Microsystems, Inc.)

ODG OpenOffice / StarOffice OpenDocument (Ver 2) Graphics Document (Sun Microsystems, Inc.)

ODH Odigo History File (Comverse, Inc. a part of Comverse Technology)

ODI OpenOffice / StarOffice OpenDocument (Ver 2) Image (Sun Microsystems, Inc.)

ODIF Open Document Interchange Format

ODL Object Definition Language

ODLVisual C ++ Type Library Source (Interface Definition Language File) (Microsoft)

ODM Opendisc Software (Opendisc)

ODM OpenOffice / StarOffice OpenDocument (Ver 2) Global Text Document (Sun Microsystems, Inc.)

ODP Oedipus

ODP OpenOffice / StarOffice OpenDocument (Ver 2) Presentation (Sun Microsystems, Inc.)

ODS NCompass Labs Internet Script

ODS Outlook Express Mailbox (Microsoft)

OFM Font (Adobe)

OFM OmniForm Form File

OFM PostScript Font Description File

OFM OfficeForms Blank Form File (Toplevel Computing)

OFN Office FileNew File (Microsoft)

OFR OptimFROG Encoded Audio (Florin Ghido)

OFT Outlook Item Template (Microsoft)

OFX Olicom Fax

OFX Open Financial Exchange File

OGF OnkoS Graphic File (OnkoS)

OGF Outrage Graphic Rows

OGG Ogg Vorbis Codec Compressed WAV File

OGG Origin Graphic File (OriginLab)

OGG Salt Lake City Game File

OGL Overlay Source Code

OGM Ogg Vorbis Compressed Video File

OGM Origin Matrix File (OriginLab)

OGO OriginPro Graphic Object File (OriginLab)

OGS Origin Script File (OriginLab)

OGW Origin Worksheet File (OriginLab)

OGX C ++ Component Gallery Exported Classes and Resources (Borland Software Corporation)

OH Overhoor (DrillAssistant) List (Efkasoft)

OH4 Overhoor (DrillAssistant) List (Efkasoft)

OHC OpenHelp Table of Contents File (Borland Software Corporation)

OHI OpenHelp Index (Borland Software Corporation)

OHL OpenHelp Link (Borland Software Corporation)

OHP DOS 7 File

OHP OpenHelp Project File (Borland Software Corporation)

OHS Bink Outbound History

OHW Overhoor (DrillAssistant) List (Efkasoft)

OID Prosa / OM Object Interaction Diagram

OIF QuickBase Web-sharable Database Interchange File

OIK Lenné3D Plant Distribution File (Lenné3D GmbH iG)

OIL Open Image Library Format

OIX Lenné3D Plant Distribution File (Lenné3D GmbH iG)

OJP 3WayPack (The Three-Mode Company)

OKS OKScript File (Mike Mardesich)

OKT Oktalyzer Tracker Module

OKX OKScript File (Mike Mardesich)

OLB AUTOGEN

OLB Automation Object Library (Microsoft Corporation)

OLB PSpice Capture Symbols Models (OrCAD)

OLB VAX Object Library

OLB Medical Terminology Challenge Data File (Delmar Learning)

OLD Old Version

OLE Object Linking and Embedding (OLE) Object

OLF OyezForms Legal Documents (UK) (Oyez)

OLI Olivetti Text File

OLK MS Mail Mailbag Lock

OLK Outlook Address Book (Microsoft)

OLL TrialDirector Object Load List

OLN Visual C ++ Outline Examples (Microsoft)

OLT Visual C ++ Outline Examples (Microsoft)

OLV OnLive! Traveler Sound File (The Digital Space Commons)

OLV OyezForms Legal Documents (UK) (Oyez)

OM Omicron Compiler File

OMA Sony Music Format File (Sony)

OMD Prosa / OM Class Model

OMF Open Media Format File

OMG OpenMG Jukebox (Sony)

OMN Omnipotent, Inc. Collection File

OMO Oracle Media Objects File

OMS Briggs Softworks Order Maven

OMS Macintosh MP3 Music Format

OMS Omega Downloader Configuration File

OMX OMAX Make Tool Path File (OMAX Corporation)

OMX Ots Media Library (Ots Labs Pty Ltd)

ON Audio Utility Tuningwrench Compressed File

OND Notes Database (IBM)

ONEdocPointer Visual ReadMe File (docPointer)

ONE OneNote Note File (Microsoft)

ONE EdgeCAM Licensing Data Ffile (Pathtrace Engineering Systems)

ONF Open Navigation Format File

ONX Onyx Graphics Postershop File

OO Free Pascal Object File for OS / 2 Version (FPC Development Team)

OOM Shroom Swap File

OOP OOP Packer Archive (TonyTown Software Ltd.)

OP Rescue Disk File

OP Origin Preprocessed Origin C File (OriginLab Corporation)

OP2 Musplay 1.72 File

OP2 Outpost 2 Saved Game

OPA Psion OPL Object File (Psion PLC)

OPC Beta 44 Job File

OPC Office Upgrade Control File (Microsoft)

OPC Omron OPC Client File

OPD OmniPage Document (ScanSoft, Inc.)

OPD Durango Interferometry Software Document (Diffraction International)

OPF Flip Album File

OPF KEPServerEX Project Configuration File (Kepware Technologies Inc.)

OPF Gemstar eBook Publisher Package (Gemstar eBook)

OPF Obsidium Project File (Obsidium Software)

OPI OmniPass Exported User (Softex, Inc.)

OPJ OrCad Project File

OPJ Origin Project File (OriginLab)

OPJ OmniPage Schedule (ScanSoft, Inc.)

OPK Origin Origin Pack File (OriginLab)

OPL Psion Organiser Programming Language Source File (Psion PLC)

OPM Quadrox Digital CCTV System Components

OPN Exact Active Options

OPN Court Opinion File (Tennessee Administrative Office of the Courts)

OPN Rebel Strip Poker Opponent File (Rebel Software)

OPN Strip Poker Deluxe Opponent File (Eagle Rock Enterprises, Inc.)

OPO Psion OPL Output Executable File (Psion PLC)

OPO Psion Organiser OPL Code (Psion PLC)

OPP IPhoto File (Keronsoft)

OPS Office Profile Settings File (Microsoft)

OPS Dynamite VSP Object Placement Style (3am Solutions (UK) Limited)

OPT Delphi Project Options (Borland Software Corporation)

OPT Developer Studio File Workspace Options (Microsoft)

OPT Options / Configuration

OPT ProWORX Nxt List Module Option File (Schneider Electric)

OPT QEMM Optimize

OPT SegueSilkTestOption Set File

OPT Psion Organiser OPL Source (Psion PLC)

OPT pcAnywhere Option Set File

OPT Business Integrator Option File (Pervasive Software Inc.)

OPW OrgPlus Organization Chart (HumanConcepts, LLC)

OPX OrgPlus Organization Chart (HumanConcepts, LLC)

OPX Exact Inactive Options

OPX Flip Album File

OPX OPL Extension DLL

OPX OrgChart Organization Diagram (Microsoft)

OPX Psion Organiser Programming Language (Psion PLC)

OQY Excel OLAP Query File (Microsoft)

OR2 Organizer Ver 2 File (IBM)

OR3 Organizer 97 File (IBM)

OR4 Organizer (IBM)

OR5 Organizer (IBM)

OR6 Organizer Data File (IBM)

OR8 Rational Rose Oracle8 Database Model Report (IBM)

ORA Oracle 7 Configuration

ORC cSound Synthesis Instruments (Csounders)

ORC Oracle 7 Script

ORC Digital Orchestrator Plus Sound File (Voyetra Turtle Beach, Inc.)

ORD BC45 Owl File

ORD OMAX Make Tool Path File (OMAX Corporation)

ORE 3WayPack (The Three-Mode Company)

ORF Descent 3 Outrage Room Format

ORF Olympus Digital Camera Raw Image File

ORG Organiser (IBM)

ORG Microcal Origin Plot

ORG Netmino File

ORG Origin File

ORG Hollywood FX Effects Organizer File (Pinnacle Systems, Inc.)

ORI Need for Speed-Hot Pursuit 2 File

ORI Original

ORIG Gen Original File

ORIGINAL Netobjects Fusion Components BBScomp Message File

ORO 3WayPack (The Three-Mode Company)

OS3 OS / 2 Warp 3 File

OSC Formula One 2001 Options File

OSC Fruitypro Samples SS_effects File

OSC Remote Installation Services Client Installation Wizard File (Microsoft)

OSD Open Software Description File (Microsoft)

OSD SoftGrid Program Description (Softricity, Inc.)

OSF Distribution Bin File

OSF ICZ OriSAFE

OSF Descent 3 Sound File (Outrage Entertainment)

OSF Opera Skin (Opera Software ASA)

OSG OSG321 Software Application Data File

OSI Osiris Database (The Shmoo Group)

OSI SunNet OSI Description File (Sun)

OSL OckamSoft Log File (Ockam Instruments, Inc.)

OSS Office Saved Search (Microsoft)

OST Exchange Offline File (Microsoft)

OST Outlook Offline File (Microsoft)

OST Tivoli Storage Manager File (IBM)

OTBNokia Phone Graphics Editor (Nokia)

P object code library file

PAL: compressed file

PART: Go! Zilla partial download file

PAS: Pascal source code

PCS: PICS animation file

PDF: Adobe Acrobat exportable document format file (displayable by Web browser); Microsoft Systems Management Server package definition file; NetWare printer definition file

PHP, PHP3: HTML pages with PHP scripts

PHTML: HTML pages containing PHP scripts; HTML interpreted by Perl

PM5: Pagemaker 5.0 file

PM6: Pagemaker 6.0 file

PNG: Graphic file

PPS: Microsoft Powerpoint Slideshow

PPT: Microsoft Powerpoint2003 presentation

PPTX: Microsoft Powerpoint2007 presentation

PRF: Windows system files, Macromedia director settings files

PSD: Adobe photoshop bitmap file

PSM: Protracker Studio model format; source data files for Epic games

PST: Microsoft Outlook Personal Folder File

PWL: Windows 95 password list file

PZA MGI PhotoSuite II / III / 4 Album File (Sonic Solutions)

PZC GraphPad Prism Script

PZD Pizazz Plus Defaults

PZF GraphPad Prism Project (GraphPad Software, Inc.)

PZF Piezoelectric Resonance Analysis Program (PRAP) Resonance Spectrum (TASITechnical Software Inc.)

PZH Presto Job (Soft SA)

PZI Pizazz Plus Graphics File

PZL UNIX Puzzle Bitmap

PZL Puzzle

PZL Jigs @ w Puzzle

PZL Lode Runner Game Puzzle

PZM GraphPad Prism

PZO Pizazz Plus Overlay

PZP Pizazz Plus Palette

PZP MGI PhotoSuite II / III / 4 Project File

PZS Pizazz Plus Settings

PZS MGI PhotoSuite II / III / 4 Slide Show File

PZT Pizazz Plus Transfer File

PZT GraphPad Prism Template

PZX Pizazz Plus Swap File

PZZ Curious Labs Compressed Poser File
PY python file

Q object code library file

Q Unknown Apple II File (found on Golden Orchard Apple II CD Rom)

Q Win95 Fax Queue

Q Quantum Compressed Archive (Cinematronics)

Q0 Q0 Graphic

Q00 Quicken 2000 File (Intuit Inc.)

Q01 Quicken 2001 File (Intuit Inc.)

Q03 QuickTax Year 2003 Return (Intuit Canada)

Q04 QuickTax Year 2004 Return (Intuit Canada)

Q1 Winamp Equalizer Settings (Nullsoft)

Q1A QuickClean Restore Point (Network Associates Technology, Inc.)

Q1Q LunarCell Plug-in File

Q1Q LunarCell Photoshop / Paint Shop Pro Plug-In (Flaming Pear Software)

Q2 Unknown Apple II File (found on Golden Orchard Apple II CD Rom)

Q2Q Flexify Photoshop / Paint Shop Pro Plug-In (Flaming Pear Software)

Q3D Quickdraw 3D File

Q3D Quest3D Interactive 3D File (Act-3D BV)

Q3O Quick3D Model

Q3X QuickTime QuickDraw 3D Extension (Apple Computer, Inc.)

Q4Q Solar Cell Photoshop / Paint Shop Pro Plug-In (Flaming Pear Software)

Q5Q SuperBladePro Preset

Q5R Melancholytron Photoshop / Paint Shop Pro Plug-In (Flaming Pear Software)

Q7Q India Ink Photoshop / Paint Shop Pro Plug-In (Flaming Pear Software)

Q8R Flood Photoshop / Paint Shop Pro Plug-In (Flaming Pear Software)

Q98 Quicken 98 File (Intuit Inc.)

Q99 Quicken 99 File (Intuit Inc.)

Q9Q BladePro Graphic Plug-in File

Q9R Glitterato Photoshop / Paint Shop Pro Plug-In (Flaming Pear Software)

Q9S Mr. Contrast Photoshop / Paint Shop Pro Plug-In (Flaming Pear Software)

QAA WinQSB Data Input File (John Wiley & Sons, Inc.)

R object code library file

R Pegasus Mail Resource File (David Harris)

R Unknown Apple II File (found on Golden Orchard Apple II CD Rom)

R Macintosh Resource Similar to RC

R REBOL Script or Data File (REBOL Technologies)

R Paradox File

R Xcode Core Rez Program (Apple Computer, Inc.)

R Progress Database Compiled Program File (Progress Software Corporation)

R Ratfor FORTRAN Preprocessor File

R00 WinRAR Split Compressed Archive (RarLab)

R01 WinRAR Split Compressed Archive (RarLab)

R02 WinRAR Split Compressed Archive (RarLab)

R03 WinRAR Split Compressed Archive (RarLab)

R04 WinRAR Split Compressed Archive (RarLab)

R05 WinRAR Split Compressed Archive (RarLab)

R06 WinRAR Split Compressed Archive (RarLab)

R07 WinRAR Split Compressed Archive (RarLab)

R08 WinRAR Split Compressed Archive (RarLab)

R09 WinRAR Split Compressed Archive (RarLab)

R1A Yamaha RM1x Dance-Music Workstation (Yamaha Corporation of America)

R1M RealOne Metadata Package (RealNetworks)

R1W Reflection Setting File (WRQ)

R2A Yamaha RS7000 Music Production Studio Sequencer (Yamaha Corporation of America)

R2A RS7000 All Data (Yahama Corporation)

R2D RISA-2D Simple Analysis & Design

R2D Reflex Ver. 2 Data File (Borland Software Corporation)

R2K Repertoire 2000 Music Database

R2P Yamaha RS7000 Music Production Studio Sequencer (Yamaha Corporation of America)

R2P RS7000 Pattern Data (Yahama Corporation)

R2S RS7000 Song Data (Yahama Corporation)

R2W Reflection Setting File (WRQ)

R3A RS7000 Sample Data (Yahama Corporation)

R3A Yamaha RS7000 Music Production Studio Sequencer (Yamaha Corporation of America)

R3D Realsoft 3D Image (Realsoft Graphics Oy)

R3D Raider3D Image File (OKYZ SA)

Game Files in RRS Violent Moto 2002

S object code library file

SLN Visual Stdio Solution

T object code library file

TAK a new lossless audio compression format

TTF a font file format

TXT windows comes with text format

TXD is a texture file format in Grand Theft Auto series games

V object code library file

VSP VideoStudio Corel VideoStudio Pro X3 Project File

V8 Covox 8-bit sound file

VAP Annotated Speech File

VBA VBase file

VBP Microsoft Visual Basic project file

VBW Microsoft Visual Basic workspace file

VBX Microsoft Visual Basic user-defined control

VCE Natural MicroSystems (NMS) unformatted sound file (used by Cool Edit)

VCF virtual card file (Netscape); Veri configuration file; Define objects for use with Sense8's WordToolkit

VCT, VCX Microsoft FoxPro Class Library

VDA Targa bitmap

Virtual Device Files for VI National Instruments LABView Products

VIFF Khoros Visualisation format

VIR Norton Anti-Virus or other antivirus products are used to identify files infected by a virus

VIV VivoActive Player streaming video files

VIZ Division's dVS / dVISE file

VLB CorelVentura library

VMF FaxWorks sound file

VOC Creative Labs Sound Blaster Sound File

VOX uses ADPCM encoded dialogue sound files; Natural MicroSystems (NMS) formatted sound files, Talking Technology sound files

VQE, VQL Yamaha Sound-VQ Locator File

VQF Yamaha Sound-VQ file (standard may appear)

VRF Oracle 7 configuration file

VRML Virtual Reality Modeling Language File

VSD Visio drawing file (flow chart or diagram)

VSL Download List File (GetRight)

VSN Windows 9x / NT Virusafe version file, used to keep all the information in the directory, when a file is accessed, the information is compared with the VSN information to ensure that they are consistent

VSS Visio template file

VST Targa bitmap

VSW Visio Workspace File

VXD Microsoft Windows Virtual Device Driver

X object code library file

XSDXML Schema describes the structure of an XML document

Z Object Code Library File

ZIP a high-density disk drive and disk