Complete file formats available in the world

ABKCorel Draw AutoBackup
ACLCorel Draw 6 keyboard accelerator
ACMUsed by Windows in the system directory
ACPMicrosoft Office Assistant Preview file
ACTMicrosoft Office Assistant Actor file
ACVOS/2 drivers that compress and decompress audio data
ADAfter Dark screensaver
ADBAppointment database used by HP 100LX organizer
ADDOS/2 adapter drivers used in the boot process
ADMAfter Dark MultiModule screensaver
ADPUsed by FaxWorks to do setup for fax modem interaction
ADRAfter Dark Randomizer screensaver
AFMAdobe font metrics
AF2ABC Flowchart file
AF3ABC Flowchart file
AIAdobe Illustrator drawing
AIFApple Mac AIFF sound
ALBJASC Image Commander album
ALLArts & Letters Library
AMSVelvert Studio music module (MOD) file
ANCCanon Computer Pattern Maker file that is a selectable list of pattern colors
ANIAnimated Cursor
APIApplication Program Interface file; used by Adobe Acrobat
APRLotus Approach 97 file
APSMicrosoft Visual C++ file
ARCLH ARC (old version) compressed archive
ARJRobert Jung ARJ compressed archive
ARTXara Studio drawing
ARTCanon Crayola art file
ASAMicrosoft Visual InterDev file
ASDWinWord AutoSave
ASMAssembler language source file
ASPActive Server Page (an HTML file containing a Microsoft server-processed script)
ASPProcomm Plus setup and connection script
ASTClaris Works "assistant" file
ATTAT&T Group 4 bitmap
AVIMicrosoft Video for Windows movie
AWDFaxView document

BAKBackup file
BATBatch file
BFCWindows 95 Briefcase document
BGBackgammon for Windows game
BIBinary file
BIFGroupWise initialization file
BINBinary file
BKSometimes used to denote backup versions
BK$Also sometimes used to denote backup versions
BKSAn IBM BookManager Read bookshelf
BMKAn A bookmark file
BMPWindows or OS/2 bitmap
BM1Apogee BioMenace data file
BRXA file for browsing an index of multimedia options 
BSPQuake map
BS1Apogee Blake Stone data file
BTMBatch file used by Norton Utilities
B4Helix Nuts and Bolts file

CC code
CABMicrosoft cabinet file (program files compressed for software distribution)
CALCALS Compressed Bitmap
CALCalendar schedule data
CASComma-delimited ASCII file
CATIntelliCharge categorization file used by Quicken
CBMicrosoft clean boot file
CCBVisual Basic Animated Button configuration
CCFMultimedia Viewer configuration file used in OS/2

Corel Chart
CCMLotus CC:Mail "box" (for example, INBOX.CCM)
CDACD Audio Track
CDFMicrosoft Channel Definition Format file
CDIPhillips Compact Disk Interactive format
CDRCore Draw drawing
CDTCorel Draw template
CDXCorel Draw compressed drawing
CELCIMFast Event Language file
CFBComptons Multimedia file
CFGConfiguration file
CGICommon Gateway Interface script file
CGMComputer Graphics Metafile
CHOS/2 configuration file
CHKFile fragments saved by Windows Disk Defragmenter or ScanDisk
CHPVentura Publisher chapter
CILClip Gallery download package
CIMSim City 200 file
CINOS/2 change control file that tracks changes to an INI file
CK1iD/Apogee Commander Keen 1 data file
CK2iD/Apogee Commander Keen 2 data file
CK3iD/Apogee Commander Keen 3 data file
CK4iD/Apogee Commander Keen 4 data file
CK5iD/Apogee Commander Keen 5 data file
CK6iD/Apogee Commander Keen 6 data file
CLASSJava class
CLPWindows Clipboard file
CLSVisual Basic Class Module
CMDCommand file for Windows NT (similar to a DOS .BAT file)
CMDDOS CP/M command file
CMDdBase-II program file
CMFCorel Metafile
CMPAddress document
CMVCorel Move animation
CMXCorel Presentation Exchange image
CNFConfiguration file used by Telnet, Windows, and other applications
CNMWindows application menu options and setup file
CNQCompuworks Design Shop file
CNTWindows (or other) system content files for the help index and other purposes
COBtrueSpace2 object
CODMicrosoft C compiler output as displayable assembler with original C as comments
COMCommand file (program)
CPDFax Cover document
CPEFax Cover document
CPIMicrosoft MS-DOS code page information file
CPLControl Panel extension
CPLCorel colour palette
CPPC++ code
CPRCorel Presents Presentation
CPTCorel Photo-Paint image
CPXCorel Presentation Exchange Compressed drawing
CRDCardfile file
CRPCorel Presents Run-Time Presentation
CRTCertificate file
CSCCorel Script
CSPPC Emcee On-Screen image
CSVComma-separated values file
CTScitex CT Bitmap
CTLUsed in general to mean a file containing control information. 
CUEMicrosoft Cue Cards data
CURWindows Cursor
CUTDr Halo bitmap
CVCorel Versions archive
CVMicrosoft CodeView information screen
CWKClaris Works data file
CWSClaris Works template
CXXC++ source code file

DATData file
DATWordPerfect Merge Data
DBFAston-Tate dBASE database
DBXDataBeam image
DCRShockwave file
DCSDesktop Color Separation file
DCXFax image (based on PCX)
DEFSmartWare II data file
DEFC++ Definition
DERCertificate file
DIBDevice-Independent Bitmap
DIFData Interchange Format spreadsheet
DIRMacromedia Director file
DIZDescription file
DLGC++ Dialogue Script
DLLDynamic-Link Library
DMFX-Trakker music module (MOD) file
DOCFrameMaker or FrameBuilder document
DOCWordStar document
DOCWordPerfect document
DOCMicrosoft Word document
DOTMicrosoft Word document Template
DPRBorland Delphi project header file
DRWMicrografx Designer/Draw
DSGDooM saved game
DSMDynamic Studio music module (MOD) file
DSPMicrosoft Developer Studio project
DSQCorel QUERY file
DSWMicrosoft Developer Studio workspace
DWGAutoCAD drawing eXchange format
DXFAutoDesk Drawing Interchange format

EMFEnhanced Windows Metafile
ENCEncore file
EPSEncapsulated PostScript image
ER1ERWin file
ERXERWin file
EVYEnvoy document
EWLMicrosoft Encarta document
EXEExecutable file (program)

FARFarandole Composer music module (MOD) file
FAVMicrosoft Outlook navigation bar
FAXFAX Type image
FH3Aldus Freehand 3 drawing
FIFFractal image file
FITSCCD camera image
FLCAutoDesk FLIC animation
FLIAutoDesk FLIC animation
FLTCorel filter
FLTStarTrekker music module (MOD) file
FMBOracle binary source code for form, version 4.0 and later
FMTOracle text format of form, version 4.0 and later
FMTMicrosoft Schedule+ print file
FMXOracle executable form, version 4.0 and later
FOGFontographer font
FONSystem font
FOTFont-related file
FPFileMaker Pro file
FP1Flying Pigs for Windows data file
FP3FileMaker Pro file
FPXFlashPix bitmap
FRMFrameMaker or FrameBuilder document
FRMOracle executable form version 3.0 and earlier
FRMVisual Basic form
FRMWordPerfect Merge form
FRXVisual Basic form stash file

GALCorel Multimedia Manager album
GCPGround Control Point file used in image processing of remote sensing data . 
GEDGraphic Environment Document (drawing)
GEMGEM metafile
GENVentura-Generated text file
GFCPatton&Patton Flowcharting 4 flowchart file
GFIGenigraphics Graphics Link presentation
GFXGenigraphics Graphics Link presentation
GIDWindows 95 global index file (containing help status)
GIFCompuServe bitmap
GIMGenigraphics Graphics Link presentation
GIXGenigraphics Graphics Link presentation
GNAGenigraphics Graphics Link presentation
GNXGenigraphics Graphics Link presentation
GRAMicrosoft Graph
GRDGrid file, used in image processing of remote sensing data often to form map projections. 
GRPProgram Manager Group
GTKGraoumftracker (old) music module (MOD) file
GT2Graoumftracker (new) music module (MOD) file
GWXGenigraphics Graphics Link presentation
GWZGenigraphics Graphics Link presentation
GZUnix Gzip compressed file

HC program header
HEDHighEdit document
HELMicrosoft Hellbender saved game
HEXMacintosh BinHex 2.0 file
HGLHP Graphics Language drawing
HLPHelp file
HOGLucas Arts Dark Forces WAD file
HPJVisual Basic Help Project
HPPC++ program header
HQXMacintosh BinHex 4.0 file
HSTHistory file
HTMHypertext document
HTMLHypertext document
HTXExtended HTML template

ICACitrix file
ICBTarga bitmap
ICMImage Color Matching profile file
ICOWindows Icon
IDDMIDI Instrument Definition
IDQInternet Data Query file
IGFInset Systems metafile
IIFQuickBooks for Windows interchange file
IMAWinImage file
IMGGEM image
INCAssembler language or Active Server include file
INFInformation file
INIInitialization file
INPOracle source code for form, version 3.0 and earlier
INSInstallShield install script
INSX-Internet sign-up file
ISOLists the files on a CD-ROM; based on the ISO 9660 CD-ROM file system standard
ISPX-Internet sign-up file
ISUInstallShield uninstall script
ITImpulse Tracker music module (MOD) file
IWIdlewild screensaver

JARJava ARchive file (a compressed file for applets and related files)
JAVAJava source code
JBFPaint Shop Pro image browser file
JFFJPEG bitmap
JIFJPEG bitmap
JMPSAS JMPDiscovery chart-to-statistics file
JN1Epic MegaGames Jill of the Jungle data file
JPGJPEG bitmap
JSJavaScript source code
JTFJPEG bitmap

KDCKodak Photo-Enhancer
KFXKoFax Group 4 image
KYEKye game data

LBMDeluxe Paint bitmap
LDBMicrosoft Access lock file
LEGLegacy document
LHAAlternate file suffix for LZH
LISOutput file produced by a Structured Query Reporting (SQR) program
LOG1. Log file
LOG2. Log file used by pokerstars for errors in their poker software
LPDHelix Nuts and Bolts file
LRCIntel Video Phone file
LSTList file
LWOLightwave Object file
LWPLotus Wordpro 96/97 file
LZHLH ARC compressed archive
LZSSkyroads data file

M3DCorel Motion 3D animation
MACMacPaint image
MADMicrosoft Access module
MAFMicrosoft Access Form
MAKVisual Basic or MS Visual C++ Project
MAMMicrosoft Access Macro
MAPMap file
MAPDuke Nukem 3D WAD game file
MAQMicrosoft Access Query
MARMicrosoft Access Report
MASLotus Freelance Graphics Smartmaster file
MATMicrosoft Access Table
MAXPaperport file
MAZHover maze data
MB1Apogee Monster Bash data file
MCCDialer10 calling card
MCSMathCAD image
MCWMicrosoft Word for Macintosh document
MDAMicrosoft Access add-in
MDBMicrosoft Access database
MDEMicrosoft Access MDE file
MDLDigital Tracker music module (MOD) file
MDLQuake model file
MDNMicrosoft Access blank database template
MDWMicrosoft Access Workgroup
MDZMicrosoft Access wizard template
MEDMusic Editor, OctaMED music module (MOD) file
MERFormat for interchanging spreadsheet/database data; recognized by Filemaker, Excel, and others
METPresentation Manager metafile
MICMicrosoft Image Composer file
MMFMicrosoft Mail File
MMMMicrosoft Multimedia Movie
MODFastTracker, StarTrekker, Noise Tracker (etc.) music module file
MODMicrosoft Multiplan spreadsheet
MOVQuickTime for Windows movie
MPEMPEG animation
MPEGMPEG animation
MPGMPEG animation
MPPMicrosoft Project file
MPPCAD drawing file format
MP3MPEG Audio Layer 3 (AC3) file
MSGMicrosoft Mail message
MSNMicrosoft Network document
MSPMicrosoft Paint bitmap
MTMMultiTracker music module (MOD) file
MVBMicrosoft Multimedia Viewer file
MWPLotus Wordpro 97 Smartmaster file

NAPNAP Metafile
NCBMicrosoft Developer Studio file
NSFLotus Notes database
NSTNoise Tracker music module (MOD) file
NTFLotus Notes database template

OBDMicrosoft Office binder template
OBDMicrosoft Office Binder
OBJObject file
OBZMicrosoft Office Binder Wizard
OCXMicrosoft Object Linking and Embedding custom control
OFNMicrosoft Office FileNew file
OFTMicrosoft Outlook template
OKTOktalyzer music module (MOD) file
OLBOLE Object Library
OLEOLE object
OPTMicrosoft Developer Studio file
ORGLotus Organiser file
OR2Lotus Organiser 2 file
OR3Lotus Organiser 97 file

P10Tektronix Plot 10 drawing
PABMicrosoft Personal Address Book
PAKQuake WAD file
PALWindows colour palette
PATCorel Draw pattern
PBKMicrosoft Phonebook
PBMPortable Bitmap
PCDKodak Photo-CD image
PCLHP Laserjet bitmap
PCSPICS animation
PCTMacintosh PICT drawing
PCXZSoft PC Paintbrush bitmap
PDFAdobe Acrobat Portable Document Format or Netware Printer Definition File
PDFPackage Definition File from Microsoft Systems Management Server
PDQPatton&Patton Flowcharting PDQ Lite file
PFAType 1 font (ASCII)
PFBType 1 font (binary)
PFCPF Component
PFMPrinter Font Metrics
PGLHP Plotter drawing
PGMPortable Graymap (bitmap)
PICPC Paint bitmap
PICLotus picture
PICMacintosh PICT drawing
PIFProgram Information File
PIFIBM PIF drawing
PIGLucas Arts Dark Forces WAD file
PINEpic Pinball data file
PINEpic Pinball data file
PIXInset Systems bitmap
PJMKS Source Integrity file
PKGMicrosoft Developer Studio application extension (similar to a DLL file)
PLPerl program
PLTHPGL Plotter drawing
PLTAutoCAD Plot drawing
PM5Pagemaker 5.0 file
PM6Pagemaker 6.0 file
P65Pagemaker 6.5 file
PNGPortable Network Graphics bitmap
PNGPaint Shop Pro Browser catalogue
PNTMacPaint graphic file
POTMicrosoft PowerPoint Template
PP4Picture Publisher 4 bitmap
PPAMicrosoft PowerPoint Add-in
PPMPortable Pixelmap bitmap
PPSMicrosoft PowerPoint slide show
PPTMicrosoft PowerPoint presentation
PRELotus Freelance presentation
PRFWindows system file
PRNPrint Table (space delimited text)
PRSHarvard Graphics for Windows presentation
PRZLotus Freelance Graphics 97 file
PSPostscript Interpreted drawing
PSDAdobe Photoshop bitmap
PSTMicrosoft Outlook Personal Folder File
PTMPolytracker music module (MOD) file
PUBVentura Publisher publication
PUBMicrosoft Publisher document
PWDMicrosoft Pocket Word document
PWZMicrosoft PowerPoint Wizard
PXLMicrosoft Pocket Excel spreadsheet

QADPF QuickArt Document
QBWQuickBooks for Windows file
QDTQuick Books data file from the Quicken UK Accountancy/Tax/Invoice program
QLBQuick Library
QRYMicrosoft Query
QTQuickTime Movie
QTMQuickTime Movie
QXDQuark XPress file

RPegasus Mail resource file
RAReal Audio sound
RAMReal Audio sound
RASSun Raster Images bitmap
RAWRaw File Format (bitmap)
RCMicrosoft Visual C++ Resource Script
RECRecorder macro
REGRegistration file
RESMicrosoft Visual C++ Resource
RLERun-Length Encoded bitmap
RMReal Audio video file
ROVRescue Rover data file
RPTMicrosoft Visual Basic Crystal Reports file
RTFRich Text Format document
RTMReal Tracker music module (MOD) file

SAMAmi Professional document
SAVSaved game file
SCCMicrosoft Source Safe file
SCDMatrix/Imapro SCODL slide image
SCDMicrosoft Schedule+ 7
SCHMicrosoft Schedule+ 1
SCNtrueSpace2 scene
SCPDial-Up Networking Script
SCRWindows screensaver
SCRFax image
SCTScitex CT bitmap
SC2Microsoft Schedule+ 7
SDLSmartDraw library
SDRSmartDraw drawing
SDTSmartDraw template
SEASelf-expanding archive (used by Stuffit for Mac files and possibly by others)
SEPTagged Image File Format (TIFF) bitmap
SHBCorel Show presentation
SHBDocument shortcut file
SHGHotspot bitmap
SHSShell scrap file
SHWCorel Show presentation
SITStuffit archive of Mac files
SLKSymbolic Link (SYLK) spreadsheet
SNDNeXT sound
SNDMac Sound Resource
SQCStructured Query Language (SQR) common code file
SQRStructured Query Language (SQR) program file
STMScream Tracker music module (MOD) file
STYVentura Publisher style sheet
SVXAmiga 8SVX sound
SYSSystem file
S3MScream Tracker 3 music module (MOD) file

TARTape Archive
TAZUnix Gzip/Tape Archive
TEXTexture file
TGATarga bitmap
TGZUnix Gzip/Tape Archive
THEMEWindows 95 Desktop Theme
THNGraphics Workshop for Windows thumbnail
TIFTag Image File Format (TIFF) bitmap
TIFFTag Image File Format (TIFF) bitmap
TIGTiger file, used by US government to distribute maps
TLBOLE Type Library
TMPWindows temporary file
TRMTerminal file
TRNMKS Source Integrity project usage log
TTFTrueType font
TWFTabWorks file
TWWTagwrite Template
T2TSonata CAD modelling software file

UDFWindows NT Uniqueness Database File
ULTUltratracker music module (MOD) file
URLInternet shortcut
USEMKS Source Integrity file

VBPVisual Basic Project
VBWMicrosoft Visual Basic workspace
VBXVisual Basic custom control
VCFVevi Configuration File; defines objects for use with Sense8's WorldToolKit
VDATarga bitmap
VIVirtual Instrument file from National Instruments LABView product
VLBCorel Ventura Library
VOCCreative Labs Sound Blaster sound
VPVentura Publisher publication
VSDVisio drawing (flow chart or schematic)
VSTTarga bitmap
VSWVisio Workspace file
VXDMicrosoft Windows virtual device driver

WADLarge file for Doom game containing video, player level, and other information
WAVWindows Waveform sound
WB1QuattroPro for Windows spreadsheet
WB2QuattroPro for Windows spreadsheet
WBKMicrosoft Word Backup
WBLArgo WebLoad II upload file
WCMWordPerfect Macro
WDBMicrosoft Works database
WEBCorelXara Web document
WGPWild Board Games data file
WIDVentura width table
WILWinImage file
WIZMicrosoft Word Wizard
WK1Lotus 123 versions 1 & 2 spreadsheet
WK3Lotus 123 version 3 spreadsheet
WK4Lotus 123 version 4 spreadsheet
WKSLotus 123 Worksheet spreadsheet
WKSMicrosoft Works document
WLFArgo WebLoad I upload file
WLLMicrosoft Word Add-In
WMFWindows Metafile
WOWGrave Composer music module (MOD) file
WPWordPerfect document
WPWNovel PerfectWorks document
WP4WordPerfect 4 document
WP5WordPerfect 5 document
WP6WordPerfect 6 document
WPDWordPerfect Demo
WPDWordPerfect Document
WPGWordPerfect Graphic
WPSMicrosoft Works document
WPTWordPerfect Template
WQ1QuattroPro/DOS spreadsheet
WQ2QuattroPro/DOS version 5 spreadsheet
WRIWrite document
WRLVirtual Reality model
WS1WordStar for Windows 1 document
WS2WordStar for Windows 2 document
WS3WordStar for Windows 3 document
WS4WordStar for Windows 4 document
WS5WordStar for Windows 5 document
WS6WordStar for Windows 6 document
WS7WordStar for Windows 7 document
WSDWordStar 2000 document
WVLWavelet Compressed Bitmap

XARCorel Xara drawing
XLAMicrosoft Excel add-in
XLBMicrosoft Excel toolbar
XLCMicrosoft Excel chart
XLDMicrosoft Excel dialogue
XLKMicrosoft Excel backup
XLMMicrosoft Excel macro
XLSMicrosoft Excel worksheet
XLTMicrosoft Excel template
XLVMicrosoft Excel VBA module
XLWMicrosoft Excel workbook / workspace
XMFastTracker 2, Digital Tracker music module (MOD) file
XR1Epic MegaGames Xargon data file
XTPXTree data file
XY3XYWrite III document
XY4XYWrite IV document
XYPXYWrite III Plus document
XYWXYWrite for Windows 4.0 document

YALArts & Letters clipart library
YBKMicrosoft Encarta Yearbook

ZUnix Gzip
ZIPZip file
ZOOAn early compressed file format

000-999Used to number old versions of files and number related data files 
12MLotus 123 97 Smartmaster file
123Lotus 123 97 file
2GR and 3GRVGA Graphics driver/configuration files under Windows
386A file for use in an 80386 or higher microprocessor
669Composer 669, Unis Composer music mod file
#01 and higherA method of numbering picture files for a roll of film that has been scanned 
$$$Used by OS/2 to keep track of archived files
@@@Screen files used in the installation and instruction on use of applications 

Have I missed any other formats..