This is an alphabetical list of filename extensions.

Contents
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
# Sym 

Sym

Ext. Description Used by
###
Temporary file program-dependent format
#24
Printer data file for 24 pin matrix printer LogoScript
#IB
Printer data file LogoScript
#nn
Part of file image Long
#SC
Printer data file LogoScript
#ST
Standard mode printer definitions LogoScript
$$$
OS/2 archive file (i.e archives.$$$, keys.$$$) OS/2
$$$
Temporary file
$?
ZX Spectrum file in HOBETA format
$00
Pipe file DOS
$DB
Temporary file dBASE IV
$ED
Editor temporary file MS C
$O1
Pipe file DOS
$VM
Virtual manager temporary file Windows 3.x
)2(
LHA archiver temporary file LHA
 ??$
Backup file P-CAD
 ??_
Microsoft packed file Expand
 ?DK
Disk image Loaddskf.exe
 ?UT
Nonpacked FTN mail (? - flavor) FTN software
 !ut
Unfinished µTorrent download µTorrent
___
Adinf table Adinf
EX_
Compressed executable file Note: EX could be any first two characters in a file extension (eg BM_ for compressed bitmap (BMP), DL_ for compressed library, etc.) Files compressed using this method have been in use on Microsoft software CDs and floppies since around 1995.
 ?Q?
Squeeze for CP/M and MS-DOS
~$~
Temporary file 1st Reader
~??
Old Backup files (.MNU to .~MN) Resource Workshop - Borland Delphi
~H
Cardfile heap AZZ Cardfile
μ
Metrowerks Codewarrior project
Π
THINK C project

#

Ext. Description Used by
0
Compressed harddisk data DoubleSpace
0B
Printer font with lineDraw extended character set PageMaker
001, 002, ...
Split parts of a single whole file HJSplit
1
Fax
1
Fax many
1
Roff/nroff/troff/groff source for manual page cawf2.zip
123
Spreadsheet Lotus 1-2-3 version 9 - Lotus 1-2-3 version 97
15U
Printer font with PI font set PageMaker
1ST
Usually README.1ST text file
2GR
286 Grabber File Win
301
Fax Super FAX 2000 - Fax-Mail 96
386
Intel 80386 processor driver Windows 3.x
386
Windows virtual device driver Win
3DMF
QuickDraw 3D Metafile QuickDraw
3DS
3D Studio Graphics format 3D Studio
3DT
Database in which the meta-data of a 3D Topicscape is held 3D Topicscape
3FX
Effect CorelChart
3GR
386 Grabber File Win
Mobile Phone Video
3T4
Binary file converter to ASCII Util3
4C$
Datafile 4Cast/2
4MD
Musical file
4SW
4DOS Swap File 4DOS
4TH
FORTH source code file ForthCMP - LMI Forth
555
16 bit per pixel image file format (5bit per component)
668
Music (the mixing is always at 12048 Hz)
669
Music (8 channels) The 669 Composer
6CM
Music (6 Channel Module) Triton FastTracker
75
75x75 dpi display font Ventura Publisher
7z
7-Zipped file
8
A86 assembler source code file
85
85x85 dpi display font Ventura Publisher
8BF
Adobe Photoshop compatibile filters/plugins
8CM
Music (8 Channel Module) Triton FastTracker
8M
Printer font with Math 8 extended character set PageMaker
8U
Printer font with Roman 8 extended character set PageMaker
8xp
Executable program for TI-83/84 Plus Graphics Calculator TI Connect
91
91x91 dpi display font Ventura Publisher
96
96x96 dpi display font Ventura Publisher

A

Ext. Description Used by
A
ADA source code file
A
Library unix
A##
AlZip Compressed Files' pieces
A11
Graphics AIIM image file
AAF
AutoPatcher file
AAS
Animation Play Script AAPlay
AB6
Datafile ABStat
AB8
Datafile ABStat
ABC
Document ABC FlowCharter 1.0
ABP
Data ABComp compressed
ABP
AVS Barcode Profile AVS Barcode Source
ABF
Adobe Binary Screen Font Adobe Software
ABK
Automatic backup file CorelDRAW
ABM
Image PALS album file
ABM
Album file (various programs)
ABR
Adobe Brush file for PhotoShop PhotoShop
ABS
Abstracts (info file)
ABS
Data file Abscissa
AC
Project backup Audit Command Language (ACL)
ACA
Project Project Manager Workbench
ACB
Archive ACB
ACB
see ACMB
ACC
Program (DR-DOS - ViewMax) GEM / resident
ACCDA
Data Microsoft Access Database Wizard (Open XML)
ACCDB
Data Microsoft Access Database (Open XML)
ACCDE
Data Microsoft Access Database Wizard (Open XML)
ACCDT
Data Microsoft Access Database Template (Open XML)
ACCDU
Data Microsoft Access Database Wizard (Open XML)
ACE
Archive ACE
ACF
Adobe Custom Filter for PhotoShop PhotoShop
ACL
Project Audit Command Language (ACL)
ACL
AutoCorrect List Microsoft Office
ACM
Audio Compression Module add-on Win
ACMB
Graphics file
ACO
Adobe Color Palette
ACT
ACTOR source code file ACTOR
ACT
Animations Works Actor (Graphics cell) Animation Works
ACT
FoxDoc Action Diagrams FoxPro
ACT
Presentation Action!
AfterDark screensaver module AfterDark
AD2
ADPCM 2-bit compressed voice file ZFAX
AD3
ADPCM 3-bit compressed voice file ZFAX
ADA
Ada source code file
ADB
Ada Package Body
ADC
Bitmap graphics (16 colors) Scanstudio
ADC
Dictionary Lingvo
ADD
OS/2 adapter device driver
ADF
Amiga Disk File unADF, UAE, WinUAE etc...
ADG
Data ADG 3D Scene
ADI
Graphics file AutoCAD
ADICHT
LabChart data acquisition file ADInstruments
ADL
MCA adapter description library QEMM
ADM
After Dark support file AfterDark
ADN
Add-in Lotus 1-2-3
ADR
After Dark support file AfterDark
ADS
Ada Package Specification
ADT
Datafile for cardfile application HP NewWave
ADT
Dictionary Lingvo
ADT
Fax AdTech
ADV
GUS device driver Gf166.com
ADX
Document Archetype Designer
ADZ
Amiga Disk Zipped (See Amiga Disk File) GZip
AEP
After Effects Project File Adobe After Effects
AF2
Flowchart ABC FlowCharter 2.0
AF3
Flowchart ABC FlowCharter 3.0
AFI
Truevision bitmap graphics
AFL
Font file (for Always) Lotus 1-2-3
AFM
Datafile for cardfile application HP NewWave
AFM
Type 1 font metric ASCII data for font installer ATM - many
AFP
Shape palette ABC FlowCharter
AFT
Template ABC FlowCharter 3.0
AFW
Workplace ABC FlowCharter 3.0
AGR
ArcView ASCII grid
AI
Vector graphics file Adobe Illustrator
AIF
see AIFF
AIFC
Sound
AIFF
Audio Interchange Format File (AIFF) Convert (c) Villena
AiM
Asm Text Mode Image File The Ultimate Draw
AIN
Archive AIN
AIN
Job schedule AutoIntern
AIO
APL programming language file transfer format file
AIS
Array of Intensity Samples graphics file Xerox
AIX
Datafile for cardfile application HP NewWave
ALC
Molecular coordinates Alchemy, RasMol
ALG
Activity Log ARCSOLO
ALL
----- (Arts & Letters) symbol and font files Arts & Letters
ALL
Filelist w/ all files FRQView
ALL
Format file for working pages Always
ALL
General printer information WordPerfect for Win
ALO
Almanac support file
ALT
Menu file WordPerfect Library
ALZ
AlZip Compressed Files
AMF
Music (Advanced Module Format) DMP
AMG
Archive AMGC
AMG
System image file ACTOR
AML
AutomationML AutomationML Group
AMR
Audio format for mobile phones (Nokia, SonyEricsson)
AMS
Adobe Monitor Setup calibration file PhotoShop
AMS
Music format
ANI
Animation cursors for Win Win95 - WinNT
ANI
Animation IconAuthor
ANM
Animation Deluxe Paint Animator
ANN
Help Annotations Windows 3.x
Ann
Multi volume ARJ archive ARJ
ANS
ANSI character graphics (animation) file ANSView
ANS
ASCII text ANSI character set NewWave Write
AOL
America On-line for Windows DLL Win
AOS
Add-On Software Nokia 9000
AP
Archive WHAP
AP
Datafile Datalex EntryPoint 90
APC
Printer driver Lotus 1-2-3
APD
Printer driver Lotus 1-2-3
APE
Monkey's Audio (Lossless) audio media players
APF
Printer driver Lotus 1-2-3
API
Adobe Printer Ink file for PhotoShop PhotoShop
API
Passed parameter file 1st Reader
API
Printer driver Lotus 1-2-3
APL
APL work space format file
APL
Support module used by Manugraphics APL products
APM
Authorware Macintosh Authorware
APP
Add-in application file Symphony
APP
Application object file dBASE Application Generator
APP
Application FoxPro
APP
Application and Application Bundle Mac OS X
APP
Executable workflow / macro file Automator
APP
Executable application file DR-DOS - NeXTstep - Atari
APP
Generated application FoxPro
APR
Employee performance review Employee Appraiser
APW
Authorware Windows Authorware
APX
Appexpert database file Borland C++ 4.5
AR7
Archive AR7
ARC
Archive ARC - PKARC/PKXARC - PKPAS - PKUNPAK - QUARK
ARC
Archive SQUASH
ARD
Map Holux - Alan
ARF
Automatic Response File
ARH
Archivers definitions file DN
ARI
Archive ARI
ARJ
Archive ARJ - ARJZ
ARK
ARC archive CP/M port of ARC file archiver
ARK
Archive QUARK
ARK
Managing your Money Archive File
ARR
Arrangement Atari Cubase
ART
First Publisher graphic file First Publisher
ART
Graphics (scrapbook) Art Import
ART
Graphics format (Another Ray Tracer) PFS:1st publisher - Art Import
ARX
Archive ARX
ASC
ASCII text file
ASC
Transport armor file PGP
ASD
Autosave file Microsoft Word
ASD
Presentation Astound
ASD
Screen driver Lotus 1-2-3
ASE
Velvet Studio Sample AWAVE
ASF
Datafile STATGRAPHICS
ASF
Screen font Lotus 1-2-3
ASF
Advanced Streaming Format (Compressed Windows audio/video) Microsoft Corporation
ASK
SYSGEN answer file RT-11
ASH
Assembly language header file TASM 3.0
ASI
ASIC language source ASIC
ASI
Assembler include file Turbo C - Borland C++
ASM
Assembler language source TASM, MASM, NASM, Yasm, FASM
ASMX
ASP.NET Web Service Microsoft Corporation
ASO
Assembler object (object-oriented) file Turbo Assembler
ASP
ASPECT source code file Procomm Plus
ASP
Association of Shareware Professionals OMBUDSMN.ASP notice
ASP
Active Server Pages of Microsoft.Net Microsoft Corporation
ASPX
ActiveX Server Pages of Microsoft.Net Microsoft Corporation
ASS
Amalgam Scene Specification Halo 2 Map Editor
ASS
Advanced SubStation Alpha (Subtitles)
AST
Adobe Color Separation table for PhotoShop PhotoShop
ASW
Authorware Star Authorware
ASX
Advanced Stream Redirector file, redirects to an ASF file (see ASF) Microsoft Corporation
ASZ
Skin AltDesk
AT2
Auto template Aldus Persuasion 2.0
AT3
Atrac 3 Sound/music file All Sony devices and programs with the Atrac 3+ specification
ATM
Adobe Type Manager data/info
ATN
Adobe Photoshop action Adobe Photoshop
ATT
AT&T Group GCGW
ATY
Produced when an association type is exported by 3D Topicscape 3D Topicscape
AU
Sun/NeXT/DEC Audio file AWAVE, GoldWave
AU
Sound (audio) file SUN Microsystems - Convert (c) Villena
AUD
Audio file AudioRack
AUP
Audacity project file Audacity
AUX
Auxiliary dictionary ChiWriter
AUX
Auxiliary references TeX/LaTeX
AVA
Publication Avagio
AVB
AntiViral Toolkit Pro Bases
AVI
Audio Video Interleaved animation file Video for Windows
AVR
Audio Visual Research AWAVE
AVS
Application Visualization System
AVT
AVATAR-coding files A3E
AW
Text file HP AdvanceWrite
AWA
Animations Works Accelerated Movie Animation Works
AWD
Microsoft Fax At Work Document Microsoft Fax At Work
AWK
AWK script/program
AWM
Animations Works Movie (as .AVI) Animation Works
AWS
Data STATGRAPHICS
Ax
Directshow filter file format
AXF
ARM Executable Image generated by the ARM tools.
AXM
Axmedis object Axmedis Tools
AZD
Amazon Software Download Amazon Software Download
AZW
DRM enabled eBook Amazon Kindle
AZZ
Data file AZZ Cardfile

B

Ext. Description Used by
B&W
Black and white graphics file atari - mac
B&W
Mono binary screen image 1st Reader
B
Batch list APPLAUSE
B_W
Black and white graphics file atari - mac
B1N
Both mono and color binary screen image 1st Reader
B30
Printer font (JLaser - Cordata) Ventura Publisher
B8
Raw graphics file (one byte per pixel) plane two PicLab
BA
Binary Archive Scifer Archiver and Compression [External Header Mode]
BAC
Compiled BASIC RT-11 BASIC-11
BAD
Bad file Oracle - many
BAD
File which covers bad blocks on disk volume (not to be moved) RT-11
BAK
Backup file
BAL
Music score Ballade
BALANCE
Balance accounting sheet file Balance
BAR
Horizontal bar menu object file dBASE Application Generator
BAR
Info Bar for GFX2EXE GFX2EXE
BAS
BASIC language source QuickBASIC - GW-BASIC - FreeBASIC
Batch file MS-DOS, RT-11
BB
Database backup Papyrus
BBL
Bibliographic reference file TeX/BibTeX
BBM
Brush Deluxe Paint
BBP
Playlist BassBox
BBS
Bulletin Board System announce or text info file
BBS
Hudson-style messagebase FTN software
BC!
Unfinished download Unfinished BitComet download (a BitTorrent client)
BCF
Card data Bingo Card Creator
BCH
Batch process object file dBASE Application Generator
BCH
Datafile Datalex EntryPoint 90
BCO
Outline font description Bitstream
BCP
Borland C++ makefile
BCT
Backup dictionary Clarion
BCW
Environment settings Borland C++ 4.5
BDC
Dictionary Lingvo
BDEF
Builder Definition Websphere Portlet Factory
BDF
Adobe Glyph Bitmap Distribution Format Adobe Software
BDF
Binary update file BUPDATE.EXE (c) TNT Techn.
BDF
Bitmap Distribution Format font file X11
BDF
Datafile Egret
BDM
Videoclip AVCHD
BDR
Border Microsoft Publisher
BDT
Dictionary Lingvo
BEZ
Outline font description Bitstream
BF2
Bradford 2 font
BFC
Briefcase Win95 Win95
BFM
Font metrics unix/Frame
BFX
Fax BitFax
BGA
Bitmap graphics
BGI
Borland Graphics Interface device driver Turbo C - Turbo Pascal
BI
BASIC include file Visual Basic - FreeBASIC
BIB
Bibliography (ASCII)
BIB
Database - not compatible with TeX format Papyrus
BIB
Literature database TeX/BibTeX
BIF
Binary Image Format b&w graphics file Image Capture board
BIK
Bink video file (RAD Video)
Binary file, usually zero-start (.com analog)
BIN
SGI Powerflip
BIN
Text mode memory dump The Draw - TUD - ACiDDraw - etc
BIO
BioniX Wallpaper playlist file BioniX Wallpaper
BIO
OS/2 BIOS
BIT
Bitmap X11
BK!
Document backup WordPerfect for Win
BK
Faxbook JetFax
BK?
Backup file
BKn
Timed backup file for document window n WordPerfect for Win
BKP
Backup file Write - TurboVidion DialogDesigner
BKW
Mirror image of font set FontEdit
BLD
BLoaDable picture BASIC
BLD
SYSGEN Build procedure file RT-11
BLEND
Blender3D Project File Blender
BLG
Backup Log ARCSOLO
BLK
Temporary file WordPerfect for Win
BM
BitMap graphics file
BM3
UIQ3 Phone backup
BMK
Help Bookmarks Windows 3.x
OS/2 or Win graphics format (BitMap Picture) QPeg - CorelDraw - PC Paintbrush - many
BMT
Ami Pro Button Ami Pro
BNA
Data Atlas Boundary
BNK
Adlib instrument bank file
BNR
Graphics Banner Banner - Poster
BOK
Shamela Library book Shamela Library Program
BOO
Book-format READIBM
BOO
Compressed file ASCII archive created by BOO (msbooasm.arc) msbooasm.arc
BPC
Chart Business Plan Toolkit
BPOLY
Data Prisms binary 3D object
BPP
Backup application Clarion
BPT
Bitmap fills file CorelDRAW
BR
Script Bridge
BRD
Eagle Layout File
BRD
Tanzzle board file Tanzzle
BRD
Cadence Allegro board file Cadence
BRK
Fax Brooktrout Fax-Mail
BRK
The Brake! Mailer REXX script The Brake!
BRL
CAD Ballistic Research Laboratory CAD
BS2
Archive BS2.EXE
BSA
Archive BSArc
BSC
Compressed Apple II file archive created by BINSCII BINSCII
BSC
Database Source Browser
BSC
Pwbrmake object file Microsoft Fortran
Half-Life\Half-Life 2 map files Valve Corporation
BSS
Casio Phone base PC-LINK
BST
BiblioTex file (BiblioTex=bibliography file) TeX
BSY
Busy flag FTN soft
BTM
Batch-to-memory (quick batch) 4dos -ndos
BTN
Makeover Button file
BUFR
Binary Universal Form for the Representation of Meteorological Data
BUG
Bugs and Problems
BUN
LucasArts Bundle File
BUP
Backup file
BUT
Button definitions Buttons!
BUY
Datafile format movie
BVn
Overflow file below insert point in Doc n WordPerfect for Win
BWB
Spreadsheet application Visual Baler
BWR
Beware (buglist) Kermit
BYU
BYU Movie BYU
BZ2
Archive bzip2
BZM
Map Blitzkrieg

C

Ext. Description Used by
C--
C-- language source Sphinx C--
C
C language source Watcom C/C++
C
Unix file archive COMPACT
C++
C++ language source
C00
Print file Ventura Publisher
C01
Typhoon wave files AWAVE
C86
C source code file Computer Innovation C86
CA
Initial cache data for root domain servers Telnet
CA?
Borland packed and split file Borland Installer
CAB
Win 95 packed file Win 95
CAC
dBASE IV executable when caching on/off (see cachedb.bat)
CAD
Drawing BobCAD-CAM
CAD
Document Drafix Windows CAD
CAL
Calendar file Windows 3.x
CAL
Spreadsheet format SuperCalc
CALS
Computer Aided Acquisition and Logistics
CALS
Support Raster Format
CAM
Casio Camera
CAN
Fax Navigator Fax
CAP
Caption Ventura Publisher
CAP
Capture file ProComm - Telix
CAS
C + ASM language source Turbo C
CAT
Catalog CP Backup - dBASE IV
CAT
Device driver digital signature Microsoft Windows
CAT
Stellarium Star Catalogue Stellarium[1][2]
CATS
Combined source ATS
CBA
Source code Creative BASIC
CBC
Fuzzy logic system CubiCalc
CBL
COBOL source code file
CBM
Compiled bitmap graphics XLib
CBR
Comic Book Reader (RAR file) CDisplay and similar
CBS
MasterWord button bar configuration file
CBT
Computer Based Training many
CBZ
Comic Book Reader (ZIP file) CDisplay and similar
CC
C++ source code file
CC
CC language source CC
CCC
Bitmap graphics (native format) Curtain Call
CCF
Communications configuration file Symphony
CCH
Chart CorelChart
CCITT
CCITT Group 3 and Group 4 Encoding
CCL
Communication Command Language file Intalk
CCO
BTX Graphics file XBTX
CCT
Print Template BobCAD-CAM
CD
CD description DN
CDA
CD-Audio Win95
CDB
Card database CardScan
CDB
Main database TCU Turbo C Utilities
CDF
Common Data Format
CDF
Cyberspace Description Format
CDF
Graphics netcdf
CDK
Document Atari Calamus
CDL
CADKey CADL Language CADKey
CDM
Disk Drivers NPA Novell NetWare
CDM
Music format (compressed)
CDR
Vector graphics format (drawing) CorelDraw!
CDT
Corel Draw Template File CorelDraw!
CDX
Compaund index file Visual FoxPro
CE
Computer Eyes Conversion Artist
CE
Main.ce The FarSide Computer Calendar
CEB
Cont. Edge Bitmap Conversion Artist
CEF
CA-Clipper Workbench Application CA Clipper
CEF
Export File
CEF
Compact Embedded Font Adobe Illustrator
CEG
Bitmap graphics Tempra Show - Edsun Continuous Edge Graphics
CEL
Animation CEL 3D Studio
CEL
Graphics Autodesk Animator - Lumena
CF
Configuration file imake
CFG
Configuration file
CFL
Chart CorelFLOW
CFM
ColdFusion Markup Language Adobe ColdFusion
CFN
Font data Atari Calamus
CFO
C Form Object internal format object file TCU Turbo C Utilities
CFP
Fax The Complete Fax Portable
CFT
CFast graphics file Disney Animation Studio
CGA
CGA display font Ventura Publisher
CGI
Common Gateway Interface script
CGM
Computer Graphics Metafile vector graphics A&L - HG - many
CH
Clipper language header CA Clipper
CH3
Chart Harvard Graphics 3.0
CH4
Presentation Charisma 4.0
CHD
Font descriptor FontChameleon
CHI
ChiWriter Document ChiWriter - Chiview
CHK
Recovered data DOS CHKDSK
CHK
Temporary file WordPerfect for Win
CHL
Configuration History Log
Compiled Help File Microsoft Windows, Help Explorer Viewer
CHN
Data Ethnograph 3
CHP
Chapter file Ventura Publisher
CHR
Character set Turbo C - Turbo Pascal
CHT
Chart Harvard Graphics 2.0 - SoftCraft Presenter
CHT
CHeaT in any program/game many
CHT
Interface file for ChartMaster dBASE
CHZ
Archive CHARC
CIF
Caltech Intermediate Format graphics file
CIF
Chapter information Ventura Publisher
CIF
Crystallographic Information File RasMol, Jmol
CiM
C Text Mode Image File The Ultimate Draw
CIX
Database index TCU Turbo C Utilities
CKB
Borland C++ 4.x editor keystroke mapping BCW.EXE
CL
COMMON LISP source code file
CLA
Source Clarion
CLASS
Java class file Java
CLD
Clipper debugger configuration file CA Clipper
CLP
Clip art graphics file Quattro Pro
CLP
Clipboard file Windows 3.x
CLP
Compiler response file CA Clipper
CLP
Graphics format PCPAINT/Pictor
CLR
Color binary screen image 1st Reader
CLR
Color definitions Photostyler
CLR
Color scheme Boxer/2
CLR
Palette file for GIS format
CLS
C++ class definition file
CLW
MFC Class Wizard information Microsoft VC++
CM
Data file CraftMan
CMB
Xtree for Windows Button Bar file
CMD
Command dBASE - Waffle
CMD
External command menu 1st Reader
CMD
OS/2 batch/REXX file OS/2
CMF
FM-music file (Creative Music File)
CMK
Card Card Shop Plus
CMM
CMM script (batch) file CEnvi
CMP
Bitmap graphics (Lead CMP compression)
CMP
Compressed data PKWare Inc. data compression library
CMP
Header file for PostScript printer files CorelDRAW
CMP
Photofinish Calibration Map Photofinish
CMP
User dictionary Microsoft Word for DOS
CMRL
Concise message routing language DOTGO
CMS
Content Management System Any Web Browser
CMU
Carnegie Mellon University Formats
CMV
Animation (CorelMove CorelDraw 4.0) CorelMove CorelDraw 4.0
CNC
CNC general program data
CND
System generation conditional file RT-11
CNF
Configuration (program - printer setup) program - printer setup
CNF
Configuration file
CNV
Temporary file WordPerfect for Win
CNV
Winword DLL used as part of an import operation (CNV=converter) Microsoft Word
COB
Calgari trueSpace2 File Format
COB
COBOL source code file
COD
Code definition table UUPC
COD
Datafile Forecast Plus - Microsoft Multiplan - StatPac Gold
COD
file uncluding CODES for any program/game many
COD
Printer code definition file Boxer/2
COD
Program compiled code FORTRAN
COD
Template source file dBASE Application Generator
COD
Videotext file
COE
Coefficient file Xilinx ISE
COL
Color palette Autodesk Animator - many
COL
Spreadsheet Microsoft Multiplan
Command (memory image of executable program) DOS
COM
Indirect command file (sequence of commands to be executed) RT-11
CON
Configuration file Simdir
CON
MSTS Consist file MSTS
CPC
Compressed image Cartesian Perceptual Compression
CPD
Script Complaints Desk
CPF
Fax The Complete Fax
CPI
ColorLab Processed Image bitmapped graphics file
CPI
MS-DOS codepage file MODE.EXE
CPL
Control panel file Windows 3.x
CPL
Presentation Compel
CPP
C++ language source Watcom C/C++
CPP
Presentation CA-Cricket Presents
CPR
Knowledge Access GCGW
CPS
----- backup of startup files by QEMM (?) autoexec.cps
CPT
Encrypted memo file dBASE
CPT
Mac file archive COMPACT PRO
CPT
Template CA-Cricket Presents
CPZ
Music text file COMPOZ
CR2
RAW image format Canon digital cameras
CRA
Advanced crack file (usually text)
CRD
Cardfile Windows 3.x - YourWay
CRD
Map Holux - Alan
CRD
Molecular coordinates CHARMM, RasMol
CRF
Cross-reference Microsoft MASM - Zortech C++, RT-11 CREF
CRK
Crack file (usually text)
CRP
Encrypted database dBASE IV
CRS
File Conversion Resource WordPerfect 5.1
CRT
Terminal settings information Oracle
CRU
Compressed file archive created by CRUSH
CS
C# source file C#
CSG
Graph Statistica/w
CSM
Borland C++ 4.x precompiled header file BCW.EXE
CSP
PC Emcee Screen Image file Computer Support Corporation
CSS
Datafile CSS - Stats+
CSS
Datasheet Statistica/w
CSS
cascading style sheet
CSV
Adjusted EGA/VGA palette CompuShow
CSV
Comma Separated Values text file format (ASCII)
CTC
Control file PC Installer
CTF
Character code translation file Symphony
CTK
CommonTime Key file CommonTime software applications
CTL
Control file dBASE IV - Aldus Setup
CTL
BATCH control file (generated by BATCH from .BAT file) RT-11
CTT
BATCH Temporary file RT-11
CTX
Ciphertext file Pretty Good Privacy RSA System
CTX
Course TeXt file some Microsoft online guides
CTX
document Creativyst Table eXchange
CUF
C Utilities Form definition TCU Turbo C Utilities
CUR
Windows resource (cursor image file) Resource Workshop - WRT - Watcom Resource Editor
CUT
Graphics format (bitmapped graphics) dr. Halo
CV4
Color file CodeView
CVP
Cover page WinFax
CVS
Graphics Canvas
CVT
Backup file for CONVERTed database file dBASE IV
CVW
Color file CodeView
CWEB
C Web
CWK
Datafile ClarisWorks, Appleworks
CXX
C++ source code file Zortech C++

D

Ext. Description Used by
D
D Programming Language source file DMD
D4D
Data Draw 4D object
D4P
Data Draw 4D Pro object
D64
Commodore 64 disk image
DAA
Direct Access Archive
DAF
Data file Digital Anchor
DAT
data RSNetWorx Project
DAT
Data file in special format or ASCII
DATS
Dynamic source ATS
DAT
Database file Clarion (programming language)
DB$
Temperature debug info Clarion Modula-2
DB$
Temporary file dBASE
DB
Database file Paradox - XTreeGold - dbvista
DB
Configuration dBASE IV - dBFast
DB
Multi Edit config ME
DB2
Database dBASE II
DB3
Database dBASE III
DBA
Database file Turbo Prolog - DataEase
DBA
DarkBasic source code
DBC
DataBaseContainer Visual FoxPro
DBD
Business data Business Insight
DBD
Debug info Clarion Modula-2
DBF
Database file dBASE III/IV - Visual FoxPro - dBFast - DataBoss - DBVista
DBG
Debugger script DOS debug - Watcom debugger
DBG
Symbolic debugging information Microsoft C/C++
DBK
Database backup dBASE IV
DBL
DIBOL source file
DBM
Datafile DataEase
DBM
Menu template DataBoss
DBO
Compiled program dBASE IV
DBPro
DarkBasicPro Project
DBS
Data file used by Managing Your Money
DBS
Database in SQL Windows format
DBS
Datafile PRODAS
DBS
Printer description file Microsoft Word, Microsoft Works
DBT
FoxBASE+ style memo FoxPro 2.x
DBT
Memo file for database w/same name dBASE IV - dBFast
DBW
Windows file DataBoss
DBX
DataBeam GCGW
DBX
AutoCAD Database AutoCAD
DBX
Archive File Outlook Express
DCA
Document Content Architecture text file IBM DisplayWrite
DCF
floppy disk image Disk Copy Fast
DCL
Delphi Control Library Borland Delphi
DCM
DCM music module AWAVE
DCP
OS/2 device code page OS/2
DCS
Bitmap graphics (CYMK format) QuarkXPress
DCS
Datafile ACT! Activity Files
DCT
Dictionary: used by many programs with program dependent format Clarion
DCT
Spell checking dictionary Harvard Graphics 3.0 - Symphony
DCT
DataBaseContainer Extension Visual FoxPro
DCU
Delphi unit (compiled) Borland Delphi
DCW
Walter Machine Programing Walter Profile Editor
DCX
Multi-page PCX graphics (common fax format) Intel - SpectraFAX
DCX
DataBaseContainer Index Visual FoxPro
DD
Macintosh file archive DISKDOUBLER
DDA
Data GLBasic ASCII 3D object
DDB
Bitmap graphics
DDB
Digidesign Database File Digidesign ProTools
DDI
Disk image DiskDupe
DDP
Device Driver Profile file OS/2
DDS
DirectDraw Surface file Microsoft Flight Simulator, other Microsoft programs
DEB
DEBUG script DOS Debug
DEF
Assembly header file Geoworks
DEF
Defaults - definitions
DEF
Linker definition file TLink - WLink...
DEM
Demonstration
DEM
Digital Elevation Model
DEM
Graphics file VistaPro
DEM
Vista DEM file Meta.exe VP3
DES
Ascii text parameter description AWAVE
desktop
Desktop Entry freedesktop.org
DEV
Device driver
DEV
SYSGEN handler build procedure RT-11
DEV
Dev-C++ project file Dev-C++
DFD
Data Flow Diagram graphic file Prosa
DFI
Outline font description Digifont
DFL
Default program settings Signature
DFM
Data Flow Diagram model file Prosa
DFM
Delphi form module Borland Delphi
DFS
Delight Sound File
DFV
Printing form (Word) Microsoft Word
DFX
Micrografx Effects DLL
DGN
Graphics file MicroStation
DGS
Diagnostics
DH
Dependency information for .ph Geoworks
DHP
Dr. Halo PIC Format graphics file Dr. Halo II - III
DHT
Datafile Gauss
DI
D Programming Language interface file DMD
DIA
Diagraph graphics file Computer Support Corporation
DIB
Device Independent Bitmap rarely used Windows 3.0 bitmap; Win - OS/2
DIC
Dictionary (e.g. from WinWord)
DIF
Borland patch data file Borland patch
DIF
Data Interchange Format Visicalc
DIF
OS/2 V2.2 Display Information File OS/2
DIF
Output from Diff command - script for Patch command
DIF
SRCCOM, BINCOM output file RT-11
DIG
Digilink AWAVE
DIG
Sound Designer 1 audio file AWAVE
DIP
Graphics
DIP
Watcom debug info processor WatcomDebugger
DIR
Dialing directory file Procomm Plus
DIR
Directory file VAX - CPS Backup
DIR
Movie MacroMind Director 4.x
DIR
Directory listing file RT-11
DIS
Distribution file VAX Mail
DIS
Thesaurus CorelDraw
DIZ
Description file (Description In Zip)
DJVU
A PDF LIKE FILE DJVU
DKB
Raytraced graphics DKBTrace
DL
Animation format (Italian origin) Display - DL Viewer
DLD
----- Lotus 1-2-3
DLG
Dialog resource script file Microsoft Windows SDK
DLG
Dialog resources DN
DLF
Dialogue Live Format Produced by Exstream Dialogue and edited by Dialogue Live Editor
DLG
Windows SDK dialog editor data file
DLG
Windows SDK dialog editor data file
DLL
Dynamic-link library Windows 3.x - OS/2
DLL
Export/import filter CorelDRAW
DLM
Microsoft File Transfer Manager Microsoft File Transfer Manager
DLP
Data DAQLab
DLS
Setup Norton Disklock
DMF
Music format (Delusion Digital Music File) Delusion
DMO
Demo Derive
DMP
Dump file (eg. screen or memory)
DMP
DUMP utility output file RT-11
DMS
Amiga file archive DISKMASHER
DNG
The Digital Negative (DNG), a publicly available archival format for the raw files generated by digital cameras. Adobe Camera RAW native file
DNT
data RSNetWorx Project
DOC
A Document, or an ASCII text file with text formatting codes in with the text. This generic extension is used by many word processors. Microsoft Word and others
DOCM
Microsoft Word 2007 Master document Microsoft Word 2007
DOCX
Office Open XML Text document Microsoft Word
DOF
Delphi project options file Borland Delphi
DOG
Screen file Laughing Dog Screen Maker
DOH
Dependency information for .poh Geoworks
DOR
Roland Digital audio file Roland
DOS
External command file 1st Reader
DOS
Network driver (eg. pkt_dis.dos)
DOS
OS/2 V3 SVGA PMI-File Svga.exe
DOS
Something for MS-DOS (e.g. msdos.dos) Win95
DOS
Text file containing DOS specific info
DOT
Line-type definition file CorelDRAW
DOT
Microsoft Word document template Microsoft Word
DOX
Text file MultiMate 4.0
DOZ
Description Out of Zip VENDINFO
DP
Calendar file Daily Planner
DP
Data file DataPhile
DPR
Default project- and state-related information Borland C++ - Delphi - C
DPX
Digital Moving Picture Exchange
DRP
Web3D File Web3D
DRS
Display Resource WordPerfect for Win
DRV
Driver
DRW
Designer vector graphics file Designer - MicroGraphix
DS
TWAIN Data Source Any twain-source must supply one xxx.ds file
DS4
Vector graphics Micrografx Designer 4.x
DSC
Celestia Deep Space Catalog file Celestia
DSC
Description file
DSC
Discard file Oracle
DSD
Database DataShaper
DSF
Data Storage Format Golden Helix
DSF
Delusion Digital Sound File Delusion
DSK
Desktop configuration BP - DN - BC++ - TP
DSK
Disk Drivers Novell NetWare
DSK
Logical disk file RT-11
DSM
Digital Sound Module DSI
DSN
Design Object System Designer
DSP
Display parameters Signature
DSP
Dynamic Studio Professional Module Dynamic Studio
DSP
Graphics display driver Dr. Halo
DSP
Norton viewer DLL Win
DSR
Driver Resource WordPerfect for Win
DSS
Screensaver file DCC
DSS
Digital Speech Standard (Sound) Digital Soup
DSS
SQL Script for .Time Framework Exaktime
DST
WAIN (Scanner spec) data source DLL Win
DSW
Borland C++ 4.x desktop layout file BCW.EXE
DSY
DAISY container file ADAKTA.EXE
DT_
Data fork of a Macintosh file Mac-ette
DTA
Data file Turbo Pascal - PC-File - Stata
DTB
Database Backup for .Time Framework Exaktime
DTF
Database file PFS - Q&A
DTL
Django template language http://www.djangoproject.com/
DTM
DigiTrekker music module AWAVE
DTO
data Directory Toolkit output
DTP
Document Timeworks / greenstreet Publisher3
DTP
Page Magic 2.0 publication Page Magic 2.0
DTP
Publication Publish-It!
DVC
Data Lotus 1-2-3
DVDPROJ
iDVD project file iDVD (Apple iLife '08)
DVI
DeVice Independent document TeX
DVP
DESQView run-file DESQView
DVP
Device parameter file AutoCAD
DW2
Drawing DesignCAD for windows
DWB
Coryphaeus Software Designers Workbench CSD
DWC
Archive DWC
DWD
DiamondWare Digitized file AWAVE
Drawing AutoCAD, IntelliCAD, PowerCAD, Drafix, etc.
DX
Text file DEC WPS/DX format - DEC WPS Plus
DXF
Dialogue Exchange Format Exstream Dialogue
DXF
Drawing Interchange File Format vector graphics AutoCAD, IntelliCAD, PowerCAD, etc.
DXN
Fax Fujitsu dexNET
DYN
Data Lotus 1-2-3

E

Ext. Description Used by
E2D
2-dimensional vector graphics file Editor included in JFire
EAS
Extended file attributes OS/2
EAR
Enterprise archive archive
EBA
Source code Emergence BASIC
EBJ
Error-checking object file Geoworks
EBQ
CITE standard electronic BQ exchange file
EC
Error checking preprosessed Goc source code Geoworks
EC
Source code Ecere SDK
ECC
Error-checking file dvdisaster
ED5
EDMICS GCGW
EDA
Ensoniq ASR disk image AWAVE
EDE
Ensoniq EPS disk image AWAVE
EDF
European data format Medical timeseries storage files
EDF
Macrocom Online Kitchen-planer
EDK
Ensoniq KT disk image AWAVE
EDL
EDL Premiere
EDQ
Ensoniq sq1,2/ks32 disk image AWAVE
EDS
Ensoniq SQ80 disk image AWAVE
EDT
Default settings VAX Edt editor
EDT
Ensoniq TS disk image AWAVE
EDT
External editors definitions DN
EDV
Ensoniq VFX-SD disk image AWAVE
EEB
Button bar for Equation Editor WordPerfect for Win
EFA
Ensoniq ASR file AWAVE
EFA
Encrypted File Archive
EFE
Ensoniq EPS file AWAVE
EFE
Ensoniq EPS instrument file AWAVE
EFK
Ensoniq KT file AWAVE
EFQ
Ensoniq SQ1/SQ2/KS32 file AWAVE
EFS
Ensoniq SQ80 file AWAVE
EFT
Ensoniq TS file AWAVE
EFT
High resolution screen font ChiWriter
EFV
Ensoniq VFX-SD file AWAVE
EFX
Fax Everex EFax
EGA
EGA display font Ventura Publisher
EKA
Internal data files Borland's Eureka
EL
ELISP source code file Emacs lisp
ELB
Synergy/DE library
ELC
Compiled ELISP code Emacs lisp
ELI
Archive ELI
ELT
Event list text file Prosa
EMD
ABT Extended MoDule AWAVE
Microsoft Enhanced Metafile
EML
Stationary Template Outlook Express
EMU
Terminal emulation data BITCOM
ENC
Encoded file - UUENCODEd file Lotus 1-2-3 - uuexe515.exe
ENC
Music Encore
END
Arrow-head definition file CorelDRAW
ENFF
Extended Neutral File Format
ENG
Dictionary engine Sprint
ENG
English documentation
ENG
Graphics file (charting) EnerGraphics
ENV
Envelope or Environments
ENV
Enveloper macro WOPR
ENV
Environment file WordPerfect for Win
EPD
Publication Express Publisher
EPI
Document Express Publisher
EPI
Encapsulated PostScript graphic file
EPS
Encapsulated PostScript (Graphics format) CorelDraw - PhotoStyler - PMView - Adobe Illustrator - Ventua Publisher
EQN
Equation filE WordPerfect for Win
ERD
Entity Relationship Diagram graphic file Prosa
ERL
Erlang source code file
ERM
Entity Relationship Diagram model file Prosa
ERR
Compiler/linker error report
ESH
Extended Shell batch file
ETH
Document Ethnograph 3
ETF
Encrypted Text File. Used in some security programs.
ETW
Proprietary format from EnterTech for the MagicSing/Mic Karaoke product line. Enter-Tech
ETX
Structure-enhanced text for some ascii text browsers
EUI
Ensoniq EPS family CD image AWAVE
EVT
Events descriptions
EVY
Document WordPerfect Envoy
EWD
Document Express Publisher for Windows
EX3
Device driveR Harvard Graphics 3.0
EXC
Exclude file for Optimize (do not process) (QEMM) QEMM
EXC
REXX source code file VM/CMS
Directly executable program DOS
EXM
MSDOS executable, system-manager compliant (HP calculator) HP calculator
EXP
Protected mode EXE by PharLap Software PharLap
EXP
Exports Library File VisualStudio
EXT
Extensions descriptions file
EXX
Intermediate file by MsgPut IBM LinkWay
EZF
Fax Calculus EZ-Fax

F

Ext. Description Used by
F
Archive FREEZE
F
Fortran language source code file (in fixed form) Many Fortran compilers
F01
Fax perfectfax
F03
Fortran language source code file (in free form) Many Fortran compilers
F2R
Farandole Linear Module Farandole
F3R
Farandole Blocked Linear Module Farandole
F4
Fortran IV source code file
F4A
Audio for Adobe Flash Player
F4B
Audio Book for Adobe Flash Player
F4P
Protected Video for Adobe Flash Player
F4V
Video for Adobe Flash Player
F77
Fortran language source code file (in fixed form) Many Fortran compilers
F90
Fortran language source code file (in free form) Many Fortran compilers
F95
Fortran language source code file (in free form) Many Fortran compilers
F96
Fax Frecom FAX96
FAC
see FACE
FACE
Usenix FACE graphics file
FAM
Famtasia Famicom image format Famtasia
FAQ
Frequently Asked Questions text file
FAR
Music format (Farandole Composer Module) Farandole
FAS
Macsyma compiled program
FAX
Fax (raster graphics in CCITT format) most Fax programs
FBM
Fuzzy Bitmap
FC
Spell checking dictionary Harvard Graphics 2.0
FCM
Binary file patch file (forward compression) jlpak10.zip
FD
Declaration file Microsoft Fortran
FD
Field offsets for compiler DataFlex
FD
Front Door' resource files FD
FDS
fwNES Famicom Disk System image fwNES
FDS
Headerless Famicom Disk System image
FDW
Form F3 Design and Mapping
FE
Data Surface Evolver 3D surface
FEB
Button bar for Figure Editor WordPerfect for Win
FEI
Fatal Error Infotable Geoworks
FES
File produced when a fileless occurrence in 3D Topicscape is exported to Windows 3D Topicscape
FF
Intelligont FIAS format
FF
Outline font description Agfa Compugraphics
FFE
Front Fareast Famicom image format
FFF
Fax defFax
FFI
Atech FastFont (AllType)
FFIVW
File Format for the Interchange of Virtual Worlds
FFT
Dca/FFT Final Form Text text file (DisplayWrite)
FFT
DCA/FFT Final Form Text text file DisplayWrite
FH3
Vector graphics Aldus FreeHand 3.x
FH4
Vector graphics Aldus FreeHand 3.x
FI
Interface file Microsoft Fortran
FIF
Fractal Image Format file
FIL
Table Data Audit Command Language (ACL)
FIL
File template Application Generator
FIL
Filelist
FIL
Files list object file dBASE Application Generator
FIL
Mirror. FIL is the name given to the saved FAT by the mirror program included in some versions of DOS and in PCTools MS-DOS -
FIL
Overlay WordPerfect
FIL
File which was moved to the Virus Vault by AVG
FILM
Filmkey film file Filmkey Player
FIN
Print-formatted text file Perfect Writer - Scribble - MINCE
FIO
Aldus PhotoStyler graphics filter
FIO
Image PALS viewer DLL
FIT
File Index Table WindowsNT
FIT
see FITS
FITS
Flexible Image Transport System
FIX
Patch file
FKY
Macro file FoxPro
FLA
Adobe Flash files' basic format
Audio codec, Audio file format
FLAME
Fractal configuration file Apophysis
FLB
Format library Papyrus
FLC
Animation format FLIC >320x200 AAPlay - Autodesk AniPro
FLD
Folder Charisma
FLI
Animation format FLIC 320x200 Autodesk Animator
FLI
TeX font library EmTeX
FLM
Film Roll AutoCAD/AutoShade
FLP
Flstudio project file Fruity Loops (FlStudio)
FLT
Data/file conversion filter (or overlay) Alsud, Microsoft Word
FLT
Filter file Micrografx Picture Publisher
FLT
MultiGen Flight
FLT
Support file - graphics filter Asymetrix ToolBook
FLX
Animation format
FLX
Compiled binary DataFlex
FLV
Flash video file Flash Video Player
FM
Database FileMaker Pro
FM1
Spreadsheet format overlay Lotus 1-2-3 release 2.x
FM3
Device driver Harvard Graphics 3.0
FM3
Spreadsheet Lotus 1-2-3 release 3.x
FMB
File Manager Button bar WordPerfect for Win
FMF
Font or icon file IBM LinkWay
FMK
Makefile Fortran PowerStation
FMO
Compiled format file dBASE IV
FMT
Format file dBASE IV - FoxPro - Clipper 5 - dBFast
FMT
Gate3 format file
FMT
Style sheet Sprint
FMV
Full Motion Video file
FN3
Font file Harvard Graphics 3.0
FND
Files searching properties Win95
FNI
FileNet Native Document FileNet
FNK
FunkTracker music module AWAVE, FunkTracker
FNM
Fannie Mae Residential Loan Data (RLD) format for mortgage submission to DO/DU. Desktop Originator
Fnn
DOS screen text font - height nn pixels fntcol13.zip
FNT
Font file many
FNX
Inactive font Exact
FO1
Font file Borland Turbo C
FO2
Font file Borland Turbo C
FOG
Fontographer Database File Fontographer3.5
FOL
Folder of saved messages 1st Reader
FON
Log of all calls Procomm Plus
FON
Terminate phonebook Terminate - Terminator - Telix
FON
Windows bitmapped font file Win
FONT
Font data unix
FOP
Freedom of the Press graphic file
FOR
Form WindowBase
FOR
Fortran language source file many
FOT
Installed Truetype font Windows Font Installer
FOX
Foxbase executable (precompiled .prg) FoxBase
FP
Final Page file FoxPro for DOS
FP
Tiff file TIFF/IT P1
FP
Video file DVICO/TVIX MPEG1 video file
FP3
Database FileMaker Pro
FP4
Database FileMaker Pro
FP5
Database FileMaker Pro
FP7
Database FileMaker Pro
FPC
Catalog FoxPro
FPD
TMT Pascal compiled unit TMT Pascal
FPM
Configuration file FoxPro for MacIntosh
FPT
Foxpro memo field tables FoxPro
FPU
Configuration file FoxPro for Unix
FPW
Floorplan drawing FloorPLAN plus for Windows
FPW
Configuration file Visual FoxPro
FR?
Packed mail FTN software
FR3
Renamed dBASE III+ form file dBASE IV
FRF
FontMonger Database file FontMonger
FRG
Uncompiled report file dBASE IV
FRL
GP-Forth library GP-Forth
FRM
Registration or other form
FRM
Report file dBASE IV - Clipper 5 - dBFast
FRM
Visual Basic Form Visual Basic
FRO
Compiled report file dBASE IV
FRP
Form PerForm PRO Plus - FormFlow
FRS
Screen Font Resource WordPerfect for Win
FRT
Additional (FPT) report description file FoxPro
FRT
GP-Forth source file GP-Forth
FRX
Main (DBF) report description file Visual FoxPro
FRX
Visual Basic binary program file Visual Basic
FSA
Applied Biosystems Genetic Analysis data file GeneScan
FSIM
Simulation File Format Loudsoft
FSL
Form Paradox for Windows
FSM
Farandole Composer WaveSample Farandole
FSPROJ
Habanero Firestarter project Habanero Firestarter
FST
Linkable program dBFast
FSX
Data Lotus 1-2-3
FTM
Fielded Text Meta - Contains schema/Meta for a Fielded Text file Fielded Text
FTM
Font file Micrografx
FTX
Declared Fielded Text Fielded Text
FTXT
text Cloanto text document
FTP
Configuration FTP Software PC/TCP
FW
Database FrameWork
FW2
Database Framework II
FW3
Database Framework III
FWEB
Fortran WEB
FX
On-line guide FastLynx
FXD
Phonebook FAXit
FXP
Foxpro executable (precompiled .prg) Visual FoxPro
FXS
FAX Transmit Format graphics file WinFax
FYF
FileLoc FyTek, Inc.

G

Ext. Description Used by
G
Data chart APPLAUSE
G16
GoldED for DOS compiled config GOLDED.EXE
G3P
data Grand Prix 3 car physics
G8
Raw graphics file (one byte per pixel) plane three PicLab - Cubicomb Picturemaker
GAM
Fax GammaFax
GB
Game Boy ROM
GB1
Game Maker backup file (can also be GB2, GB3, etc.)
GBA
Game Boy Advance ROM
GBC
Game Boy Color ROM
GBL
Global definitions VAXTPU editor
GBL
Global module in Basic programs
GBR
GIMP brush
GC1
Lisp source code Golden Common Lisp 1.1
GC3
Lisp source code Golden Common Lisp 1.3
GCA
IBM GOCA GCGW
GCD
Graphics
GCD
General content descriptor Wireless devices
GCF
Game cache file Steam content delivery system
GD3
Game Doctor Super NES ROM image
GDF
General Data Format for Biomedical Signals Biomedical signal processing, Brain Computer Interfaces
GDF
Dictionary file GEOS