File Formats And Extensions

Uncharacteristic Extensions And File Format

000-999 used to number old (backup) versions of files (for example, CONFIG.SYS when changed by an installation program); also used to number related data files for multiple users of a small-scale PC application
12M Lotus 123 97 Smart master file
123 Lotus 123 97 file
2GR and 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 for computer presentation
$$$ Used by OS/2 to keep track of archived files
@@@ Screen files used in the installation and instruction on use of such applications as Microsoft Code view for C

Extensions And File Format Starting With A

ABK AMOS Basic data file
ABK Corel Draw Auto Backup
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 Multi Module 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
AIFC Similar to AIF
AIFF Similar to AIF
AIS ACD See Image Sequence file
ALB JASC Image Commander album
ALL Arts & Letters Library
AMOS AMOS Basic code
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
ARI Aristotle audio file
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
ASF Microsoft Advanced Streaming Format file
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
ASX Cheyenne Backup script
ASX Microsoft Advanced Streaming Redirector file
ATT AT&T Group 4 bitmap
AU UNIX sound file
AVI Microsoft Video for Windows movie
AWD FaxView document

Extensions And File Format Starting With B

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 and BK$ 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
BOT LinkBot document
BPX Lumena BigPix
BRX A file for browsing an index of multimedia options
BSP Quake map
BS1 Apogee Blake Stone data file
BS_ Microsoft Bookshelf Find Menu shell extension
BTM Batch file used by Norton Utilities
BUN CakeWalk Audio Bundle file (a MIDI program)
BUP Backup file (rare)
B4 Helix Nuts and Bolts file

Extensions And File Format Starting With C

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)
CCO CyberChat data file
CCT Macromedia Director Shockwave cast
CCX CorelDraw file
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
CER Certificate file (MIME x-x509-ca-cert)
CFB Comptons Multimedia file
CFG Configuration file
CGA CGA (Color Graphics Adapter) graphics data
CGI Common Gateway Interface script file
CGM Computer Graphics Metafile
CH OS/2 configuration file
CHA mIRC Chat file
CHA Character data file in some games (example: Diablo)
CHK File fragments saved by Windows Disk Defragmenter or ScanDisk
CHM Compiled HTML file
CHP Ventura Publisher chapter
CHT ChartViewer file
CHT Harvard Graphics vector file
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
CLB Corel Library
CLC Corel Catalog
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 with varying internal formats
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 Cobol code
COB trueSpace2 object
COD Microsoft C compiler output as displayable machine language/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
CSS Cascading Style Sheet file (MIME)
CST Macromedia Director "Cast" (resource) file
CSV Comma-separated values file
CT Scitex CT Bitmap
CT A graphic file associated with the Paint Shop Pro Graphic Editor
CTL Used in general to mean a file containing control information. FAXWorks uses it to keep information about each fax sent and received.
CTY SimCity's city
CUE Microsoft Cue Cards data
CUR Windows Cursor
CUT Dr Halo bitmap
CV Corel Versions archive
CV Microsoft CodeView information screen
CVP Kodak file
CWK Claris Works data file
CWS Claris Works template
CXT Macromedia Director protected (not editable) "Cast" (resource) file
CXX C++ source code file

Extensions And File Format Starting With D

DAT Data file
DAT WordPerfect Merge Data
DBF Ashton-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 Documentation 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
DQY Microsoft Excel ODBC query 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
DTF Symantec Q&A relational database data file
DUN Microsoft Dial-up Networking Export file
DV Digital video file (MIME)
DWD DiamondWare digitized file
DWG AutoCAD drawing, or older Generic CADD drawing format
DXF Drawing Interchange (eXchange) format,a text representation of the binary DWG format
DXR Macromedia Director protected (not editable) movie file

Extensions And File Format Starting With E

EGA EGA (Enhanced Graphics Adapter) graphics data
EMF Enhanced Windows Metafile
EML Microsoft Outlook Express mail message (MIME RFC 822)
ENC Encore file
EPS Encapsulated PostScript image
ER1 ERWin file
ERX ERWin file
EVY Envoy document
EWL Microsoft Encarta document
EXC Microsoft Word Exclusion Dictionary
EXE Executable file (program)

Extensions And File Format Starting With F

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
FCL Cyber Audio Library link file
FDF Adobe Acrobat Forms Document file
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
FML File Mirror List (GetRight)
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
FND Microsoft Explorer Saved Search file (Find applet)
FNG Font group file (Font Navigator)
FOG Fontographer font
FON System font
FON ProComm Plus call report
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
FTS Full-Text Search index file resulting from using Find in the Windows help system Can be erased; will be rebuilt when needed
FW3 Framework III file
FW4 Framework IV file

Extensions And File Format Starting With G

GAL Corel Multimedia Manager album
GCD Generic (TM) CADD drawing (later versions)
GCP Ground Control Point file used in image processing of remote sensing data often to form map projections. CHIPS (CopenHagen Image Processing System) uses these files.
GED Graphic Environment Document (drawing)
GEM GEM metafile
GEM Ventura/GEM drawing
GEN Ventura-Generated text file
GetRight GetRight Unfinished-Download 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
GKS Gravis GripKey document
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. CHIPS (CopenHagen Image Processing System) uses these files
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

Extensions And File Format Starting With H

H C program header
HDM HDML document
HDML HDML document
HED HighEdit document
HEL Microsoft Hellbender saved game
HEX Macintosh BinHex 2.0 file
HGL HP Graphics Language drawing
HI High score table
HIG High score table
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 Mark-up Language document
HTML Hypertext Mark-up Language document
HTT Microsoft Hypertext Template
HTX Extended HTML template

Extensions And File Format Starting With I

ICA Citrix file
ICB Targa bitmap
ICL Icon Library file (an industry standard)
ICM Image Color Matching profile file
ICO Windows Icon
IDD MIDI Instrument Definition
IDF MIDI Instrument Definition (Windows 95 required file)
IDQ Internet Data Query file
IDX Symantec Q&A relational database index file
IFF Amiga Interchange File Format
IGF Inset Systems metafile
IIF QuickBooks for Windows interchange file
ILBM A bitmap (graphic image) file
IMA WinImage file
IMG GEM paint image
INC Assembler language or Active Server include file
INF Information file
INFO Amiga icon 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
IOF Findit document
IQY Microsoft Internet Inquiry 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
ITS Internet document set (possibly a Microsoft file)
IW Idlewild screensaver

Extensions And File Format Starting With J

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 compressed bitmap
JIF JPEG compressed bitmap
JFIF JPEG compressed bitmap
JMP SAS JMPDiscovery chart-to-statistics file
JN1 Epic MegaGames Jill of the Jungle data file
JPE JPEG file
JPEG JPEG ("Joint Picture Expert Group") compressed bitmap
JPG JPEG compressed bitmap
JS JavaScript source code
JTF JPEG bitmap

Extensions And File Format Starting With K

KDC Kodak Photo-Enhancer
KFX KoFax Group 4 image
KYE Kye game data

Extensions And File Format Starting With L

LBM Deluxe Paint bitmap (Amiga IFF-ILBM file)
LDB Microsoft Access lock file
LEG Legacy document
LES Logitech Entertainment system game profiles (same as REG file)
LHA Alternate file suffix for LZH
LIB Library
LIS Output file produced by a Structured Query Reporting (SQR) program
LLC LapLink saved connection file
LNK Windows shortcut file
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

Extensions And File Format Starting With M

M1V MPEG-related file (MIME type 'mpeg')
M3D Corel Motion 3D animation
M3U MPEG URL (MIME audio file)
MAC MacPaint image
MAD Microsoft Access module
MAF Microsoft Access Form
MAG Magic Mail Monitor mailbox file
MAGIC Magic Mail Monitor mailbox file
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
MHT MHTML document (MIME)
MHTM MHTML document (MIME)
MHTML MHTML document (MIME)
MI Miscellaneous
MIC Microsoft Image Composer file
MID MIDI music
MMC Media Catalog
MMF Microsoft Mail File
MMM Microsoft Multimedia Movie
MOD Noise Tracker, FastTracker, StarTrekker (etc.) music module file
MOD Microsoft Multiplan spreadsheet
MOV QuickTime for Windows movie
MPA MPEG-related file (MIME type 'mpeg')
MPE MPEG animation
MPEG MPEG ("Motion-PEG") animation
MPG MPEG animation
MPP Microsoft Project file
MPP CAD drawing file format
MP2 MPEG Audio Layer 2 file (MIME video file)
MP3 MPEG Audio Layer 3 (AC3) file
MSG Message
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
MVX Mixer file
MWF Promotion animation
MWP Lotus Wordpro 97 Smartmaster file

Extensions And File Format Starting With N

NAP NAP Metafile Vector image
NCB Microsoft Developer Studio file
NFO Information file
NIL Norton Icon Library file (EasyIcons-compatible)
NLU Norton Live Update E-Mail Trigger file
NSF Lotus Notes database
NST Noise Tracker music module (MOD) file
NTF Lotus Notes database template
NWS Microsoft OutlookExpress news message (MIME RFC822)

Extensions And File Format Starting With O

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
OLD Old version of a file
OLE OLE object
OPT Microsoft Developer Studio file
OQY Microsoft Excel Olap query file
ORG Lotus Organiser file
OR2 Lotus Organiser 2 file
OR3 Lotus Organiser 97 file
OSS Microsoft Office Search file
OST Microsoft Exchange Offline file
OTL Super NoteTab template file (Fookes)

Extensions And File Format Starting With P

P10 Tektronix Plot 10 drawing
P65 Pagemaker 6.5 file
P7C Digital ID file (MIME)
P7M PKCS#7 Digital ID file (MIME)
PAB Microsoft Personal Address Book
PAK Quake WAD file
PAL Windows colour palette
PAS Pascal source code (Borland)
PAT Corel Draw pattern
PCP Symantec Live Update Pro file
PBK Microsoft Phonebook
PBM Portable Bitmap
PCD Kodak Photo-CD image
PCD P-Code compiled test scripts as in Microsoft Tst and Microsoft Visual Test
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
PDB 3Com Palmpilot database file
PDF Package Definition File from Microsoft Systems Management Server Verifies installed packages when performing an inventory scan of a client
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)
PHP PHP generated document
PIC PC Paint bitmap
PIC Lotus picture
PIC Macintosh PICT drawing
PICT Mac PICT image file
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
PIX Island Graphics
PJ MKS Source Integrity file
PKG Microsoft Developer Studio application extension (similar to a DLL file)
PL Perl program
PLS MPEG PLayList file (used by WinAmp)
PLT HPGL Plotter drawing
PLT AutoCAD Plot drawing
PM5 Pagemaker 5.0 file
PM6 Pagemaker 6.0 file
PNG Portable Network Graphics bitmap
PNG Paint Shop Pro Browser catalogue
PNT MacPaint graphic file
PNTG 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
PRC 3Com Palmpilot resource (text or program) file
PRE Lotus Freelance presentation
PRF Windows system file
PRF Macromedia Director settings file
PRN Print Table (space delimited text)
PRS Harvard Graphics for Windows presentation
PRT A print-formatted file
PRZ Lotus Freelance Graphics 97 file
PS Postscript Interpreted drawing
PSD Adobe Photoshop bitmap
PST Microsoft Outlook Personal Folder File
PT Kodak Precision Transform
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

Extensions And File Format Starting With Q

QAD PF QuickArt Document
QBW QuickBooks for Windows file
QDT Quick Books data file from the Quicken UK Accountancy/Tax/Invoice program
QIC Microsoft Backup file
QIF QuickTime-related image (MIME)
QLB Quick Library
QRY Microsoft Query
QST Quake Spy Tab file
QT QuickTime Movie
QTI QuickTime-related image
QTIF QuickTime-related image
QTM QuickTime Movie
QTP QuickTime Preferences file
QTS Mac PICT image file
QTS QuickTime-related image
QTX QuickTime-related image
QXD Quark XPress file

Extensions And File Format Starting With R

R Pegasus Mail resource file
RA Real Audio sound
RAM Real Audio sound
RAR RAR compressed archive (Eugene Roshall's format)
RAS Sun Raster Images bitmap
RAW Raw File Format (bitmap or generic data)
RC Microsoft Visual C++ Resource Script
RDF Resource Description Framework file (related to XML and metadata)
REC Recorder macro
REG Registration file
RES Microsoft Visual C++ Resource
RFT Revisable Form Text (part of IBM's DCA or Document Content Architecture)
RLE Run-Length Encoded bitmap
RM Real Audio video file
RMD Microsoft RegMaid document
RMF Rich Map Format (used by 3-D game editors to store a map)
RMI MIDI music
RMM Real Player sound file
RNX Real Player sound file
ROV Rescue Rover data file
RPT Microsoft Visual Basic Crystal Reports file
RTF Rich Text Format document
RTM Real Tracker music module (MOD) file
RTS RealAudio's RTSL document
RV Real Video clip
RVP Microsoft Scan Configuration file (MIME)

Extensions And File Format Starting With S

SAM Ami Professional document
SAV Saved game file
SBK Creative Labs Soundfont 1.0 Bank file (Soundblaster)
SBL Shockwave Flash object
SCC Microsoft Source Safe file
SCD Matrix/Imapro SCODL slide image
SCD Microsoft Schedule+ 7
SCF Windows Explorer command file
SCH Microsoft Schedule+ 1
SCN trueSpace2 scene
SCO High score table
SCP Dial-Up Networking Script
SCR Windows screensaver
SCR Fax image
SCT Scitex CT bitmap
SC2 Microsoft Schedule+ 7
SD2 Sound Designer 2 file
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 6.0 4 color
SES Cood Edit Session file (common digital audio editor file)
SET Setup file
SFX RAR self-extracting archive
SF2 Creative Labs Soundfont 2.0 Bank file (Soundblaster)
SHB Corel Show presentation background
SHB Document shortcut file
SHG Hotspot bitmap
SHS Shell scrap file
SHT S-HTML document
SHTML S-HTML document
SHW Corel Show presentation
SIT Stuffit archive of Mac files
SKL Macromedia Director resource file
SL PACT's Save Layout extension
SLK Symbolic Link (SYLK) spreadsheet
SMI Real Player sound file
SMIL Real Player sound file
SND NeXT sound
SND Mac Sound Resource
SQC Structured Query Language (SQR) common code file
SQR Structured Query Language (SQR) program file
SPL Shockwave Flash Object
SSM Real Player Standard Streaming Metafile
STM Scream Tracker music module (MOD) file
STY Ventura Publisher style sheet
SVX Amiga 8SVX sound
SWF Shockwave Flash Object
SYS System file
SWA Shockwave audio file in Macromedia Director (an MP3 file)
SWF Shockwave Flash object
S3M Scream Tracker 3 music module (MOD) file

Extensions And File Format Starting With T

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
TPL CakeWalk Audio Template 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
TZ Old compression format file
T2T Sonata CAD modelling software file

Extensions And File Format Starting With U

UDF Windows NT Uniqueness Database File
UDL Microsoft Data Link
ULT Ultratracker music module (MOD) file
URL Internet shortcut
URLS GetRight URL list
USE MKS Source Integrity file
USR User file (preferences)
UU UU-encoded file
UUE UU-encoded file

Extensions And File Format Starting With V

VBA VBase file
VBP Visual Basic Project
VBW Microsoft Visual Basic workspace
VBX Visual Basic custom control
VCE NMS file...audio-related, used by Cool Edit
VCF Vevi Configuration File; defines objects for use with Sense8's WorldToolKit
VDA Targa bitmap
VGA VGA (Video Graphics Array) graphics data
VI Virtual Instrument file from National Instruments LABView product
VIR File identified as a virus-infected file by Norton AntiVirus and possibly others
VIV VivoActive Player Streaming Video file
VLB Corel Ventura Library
VOC Creative Labs Sound Blaster sound
VP Ventura Publisher publication
VQE Yamaha Sound-VQ Locator file
VQF Yamaha Sound-VQ file (possible emerging standard)
VQL Yamah Sound-VQ Locator file
VRML A VRML file
VSD Visio drawing (flow chart or schematic)
VSL Download List file (GetRight)
VST Targa bitmap
VSW Visio Workspace file
VXD Microsoft Windows virtual device driver

Extensions And File Format Starting With W

WAB Microsoft Outlook file
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
WIN Targa clip
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
WML WML document
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 (bitmap or vector)
WPS Microsoft Works document
WPT WordPerfect Template
WQ1 QuattroPro/DOS spreadsheet
WQ2 QuattroPro/DOS version 5 spreadsheet
WRI Write document
WRL Virtual Reality model
WRZ Another VRML fileject
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
WWL Microsoft Word add-in file

Extensions And File Format Starting With X

XAR Corel Xara drawing
XBM A MIME 'xbitmap' image
XIF Wang imaging file (comes with Windows 95)
XLA Microsoft Excel add-in
XLB Microsoft Excel toolbar
XLC Microsoft Excel chart
XLD Microsoft Excel dialogue
XLK Microsoft Excel backup
XLL Microsoft Excel add-in file
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
XML eXtensible Mark-up Language document
XNK Microsoft Exchange shortcut file
XR1 Epic MegaGames Xargon data file
XTP XTree data file
XWF Yamaha XG Works file (MIDI sequencing)
XY3 XYWrite III document
XY4 XYWrite IV document
XYP XYWrite III Plus document
XYW XYWrite for Windows 4.0 document
X16 Macromedia Extra (program extension), 16 bit
X32 Macromedia Extra (program extension), 32 bit

Extensions And File Format Starting With Y

YAL Arts & Letters clipart library
YBK Microsoft Encarta Yearbook

Extensions And File Format Starting With Z

Z Unix Gzip Compressed
ZIP Zip file Compressed archive
ZOO An early compressed file format