What do file extensions mean on various computer platforms?

Below are listed file name extensions we have encountered in the course of our file conversions on the following platforms:

• IBM compatibles
• Amiga
• Apple
• Atari
• CP/M (various)
• UNIX

• 1ST Read Me ASCII text files named README.1ST
• 2GR Windows DOS display grabber for standard mode
• 386 Windows virtual device driver for 386 enhanced mode
• 3GR Windows DOS display grabber for enhanced mode
• 8B Adobe Photoshop 2.5 plug-in
• ABR Adobe Photoshop 2.5 brushes and patterns
• ACB IFF Brushes and ACBM Files (see BBM)
• ACO Adobe Photoshop 2.5 color system palette
• ACT Adobe Photoshop 2.5 custom color table/Actor Source code file
• AD After Dark module
• ADEX
• ADM After Dark multimodule
• ADO Adobe Photoshop 2.5 duotone options
• ADR After Dark random module
• AFM Adobe font metrics file (Mac/OS2 format)
• AI Adobe Illustrator file, Photoshop patterns
• AI Illustrator 88, 3.0
• AIF Macintosh AIFF audio files
• ALL WordPerfect printer definitions file
• AMG Actor system images file
• ANI The first image of IFF animation files
• ANS ANSI text file
• AOL America On-Line access program file
• API Adobe Photoshop 2.5 printing inks profiles
• ARC Archive file
• ASC ASCII text file; ASCII Smart a) form-feeds become hard page-breaks, b) carriage returns become conditional soft/hard returns, c) white space padding becomes formatting in tabs; ASCII Standard: a), but b) hard & soft returns become hard returns, no c); ASCII Stripped: advantage for DTP, a) strip page-breaks, b) strip soft-returns for DTP reformatting
• AVI Video for Windows until 320x200x8Bps RLE too, 160x120x16/24 Bps
• AWB At Work binary file bundle
• AWP WinFax PRO unsigned key file
• AWS WinFax PRO signed key file
• BAK Backup file
• BAS BASIC source code file
• BAT DOS batch file
• BBM IFF Brushes and ACBM Files (see ACB)
• BIN Binary source code file
• BK! Wordperfect Backup file BMP Windows 3.0 / 3.1 / OS/2 Bitmap
• BMP Windows Bitmap format
• BRO CompuServe Navigator services file
• CAL SuperCalc spreadsheet file/Windows calendar data file
• CAL Supercalc
• CCH CorelDRAW! icon, Corel Chart
• CDR CorelDRAW! file
• CDR CorelDraw! icon
• CDR CorelDRAW!
• CEG Edsun Continuous Edge Graphics (Modes d, f)
• CFG Configuration File/Adobe font installer file
• CGM Drawperfect
• CGM American National Standards Institute (ANSI) Computer Graphics Metafile
• CGM Computer Graphics Metafile
• CHP Ventura Publisher document
• CLS Actor class library file
• CMD dBase command file
• CMP Microsoft Word compare file
• CMX Corel Presentation Exchange
• CNV Microsoft Word conversion file
• COB COBOL source code file
• COM DOS command file
• CPL Control Panel module file
• CPT Compact Pro archive (Macintosh)
• CRD Windows Cardfile data file
• CSV Comma Separated Values data file/Lotus Organizer 1.x
• CTF Compressed Tiff
• CUR Windows cursor file
• CUT Dr Halo, Halovision, some scanners
• CVP Passport image photo unit (Cannon/Kodak?) 512x512 24 Bps
• CVP WinFax PRO cover page
• CVR WinFax PRO cover page text
• DAT Framegrabber Video 1000/2000 (Fricke/Berlin)
• DAT Data file
• DB Database/Paradox table data file
• DB2 dBase II data file
• DBF dBASE II, III, II PLUS
• DBF dBase III, IV data file
• DBT dBase text file
• DCS Desktop Color Separation
• DCX FAX Multiple PCC file format
• DEF Windows system definition file
• Degas Standard Atari ST paint program low res colour (.PI1), medium res col. (.PI2), high res mono (.PI3)
• DEV DOS device drivers
• DIB Windows 3.0, 3.1, and OS/2
• DIB Device Independent Bitmap file
• DIF Data Interchange Format (e.g. Visicalc)
• DIF Data Interchange Format
• DL DL animations run in realtime
• DLL Windows Dynamic Link Library
• DOC Microsoft Word document file
• DOT Microsoft Word template file
• DP Common Ground document
• DRV DOS/Windows device drivers
• DRW Micrograph 2.x, 3.x
• DRW Micrographix Designer draw file
• DRW Freelance or Freelance Plus drawing file
• DTA Kontron image analysis, ZEISS DSM-series of digital microscopes
• DXF AutoCAD DXF: plotterformat
• DXF AutoCAD Drawing Interchange Format
• ECA hDC action editor file
• EFF Aldus Gallery Effects plug-in
• EPS Encapsulated Postscript file
• EPS CorelTRACE!, Illustrator 88 3.0
• EPS Encapsulated PostScript
• ERR Error log file
• EXE DOS/Windows executable command file/DOS self-extracting archive
• F Paradox form files
• FH3 FreeHand 3.0 file
• FLC Autodesk Animator Pro FLIIC's
• FLI Animator animation file
• FLI Autodesk Animator FLIC's run in realtime. Quckfli, Aaplay
• FLM Uncompressed files from the Screen machine FAST-Electronic
• FLT Aldus filter
• FMT dBase screen format file
• FNT Font file
• FOG Fontographer font data file
• FON Windows GDI-loadable screen font
• FOT TrueType font resource file
• FRM dBase report form file
• FTM WinFax PRO events list
• FXD WinFax PRO sent fax
• FXM WinFax PRO multiple page fax for mail forwarding
• FXR WinFax PRO received fax
• FXS WinFax PRO attachment
• GEM GEM file ; see also IMG, XIMG
• GEM GEM metafile
• GIF used by many machines (IBM, Macintosh Atari, Commodore) with many applications GIF87a...GIF89a STandard
• GIF Graphics Interchange Format - CompuServe Bitmap
• GIF CompuServe Graphics Interchange Format
• GL Sequential overview of the images included in GRASP files
• GLY Microsoft Word glossary file
• GRP Windows Program Manager group file
• GUI Guide document files
• H-PGL HP Plotter files for HP graphics language
• HGL HP Graphic Language
• HLP Windows/DOS help file
• HQX BinHex 4 file (Macintosh)
• ICO Windows icons
• ICO Custom Windows icon
• ICR WordPerfect initial caps resource file
• IDX CompuServe Navigator index file
• IFF IBM and Commodore Deluxe Paint
• IFF ILBM Amiga Interchange File Format by Electronic Arts for sound (8SVX), music (SMUS), graphics (ILBM), animation (ANIM)
• IFF ACBM old format used by Commodore
• IFF PBM PCs
• IFF Amiga file
• IM KO-23 satellite with 109 block error correction
• IMG Digital Research GEM, shared with Atari ST
• IMG Kontron image analysis, ZEISS DSM-series of digital microcopes
• IMG GEM image file
• INF Installation information file
• INI Windows INI files
• INI Windows initialization file
• JFIF 8R8, 9R6 Screen Machine II compatibility JFIF with JIF
• JIF Baseline JPEG 9R6 (Image Alchemy 1.0-1.5), Lossless JPEG
• JPEG See JPG
• JPG Baseline JPEG 8R8
• JPG JPEG-compressed file
• JPG JPEG Bitmap
• JTF TIFF with JPEG compression
• LAB Label file/WordPerfect label definition
• LBL dBase label file
• LBM Deluxe Paint, both IBM and Commodore
• LEX Dictionary/thesaurus file
• LGO Windows startup logo code file
• LOD Windows loadable modules
• LOG Log file of errors/installations
• LRS WordPerfect language resource file
• LTR Letter file
• LZH LHArc archive file
• MAC Macintosh Paint (MacPaint] format
• MAK Visual Basic make file
• MCW Microsoft Word for the Macintosh file
• MDM AOL modem profile file
• ME Common extension for text files named READ.ME
• MID MIDI music file
  
• MOD Amiga music files can be played on PC-speakers or Soundblaster. For soundblaster there must be a SET BLASTER command in the autoexec.bat (The MOD Playes is based on a PD OBJ file by Marc Cox)
• MSG Message file/CompuServe Navigator message/WinFax PRO message
• MSP MS-Paint, Windows 2.0
• NDX dBase index file
• NEO Atari Neochrome (1st Atari paint package) files
• PAL CorelDRAW! palette file
• PAT CorelDRAW! pattern file
• PB CAS file
• PBK WinFax Lite/WinFax 2/DosFax
• PCC CorelPHOTO-PAINT!
• PCD Kodak Photo CD format
• PCD Kodak Photo CD Base format 768x512
• PCL HP PCL printer driver
• PCT MAC PICT
• PCT Macintosh PICT and PICT2
• PCX Windows ZSoft PC Paintbrush: shared with Atari ST ver 1-4
• PCX CorelPHOTO-PAINT!
• PCX PC Paintbrush format
• PFA Adobe Type 3 Font
• PFB Adobe Type 1 Font
• PFB Adobe PostScript Type 1 printer file
• PFL Freelance or Freelance Plus portfolio file
• PFM Adobe PostScript Type 1 font metrics file
• PGM DOS program overlay file
• PIC Lotus 1-2-3 graphics file
• PIC MACintosh PICT in 1,2,4,8 BPS
• PIC Lotus PIC
• PICT/PICT2 MACintosh PC Paint, Pictor
• PIF IBM PIF
• PIF Windows program information file for DOS applications
• PIT PackIt II or III compression file (Macintosh)
• PIX Graphic file
• PKG AppleLink package file
• PLT HP Plotter HPGL
• PLT AutoCAD plot files
• PLX CompuServe Navigator message file
• PM3 Aldus PageMaker 3.0 document
• PM4 Aldus PageMaker 4.0 document
• PM5 Aldus PageMaker 5.0 document
• PMC A4TECH Scanner
• PNM UNIX Portable Bitmap 1,8,24 Bps (Jef Poskanzer)
• PNT Mac Paint
• PRE Freelance graphics, often part of the Lotus Amipro PC package
• PRG dBase procedure file
• PRN PCL print file
• PRS Norton Desktop viewer file
• PS PostScript print file (placeable)
• PS2 IBM PS/2 system driver
• PSD Adobe Photoshop 2.5 file
• PT3 Aldus PageMaker 3.0 template
• PT4 Aldus PageMaker 4.0 template
• PT5 Aldus PageMaker 5.0 template
• PUB Aldus PageMaker publication file
• PUB Ventura publication file
• PX Paradox primary index file
• PX1 Pixel Paint
• PXR Pixar format
• QDT Quicken data file
• QEF Q + E files
• QRY Query file
• QXD QuarkXPress Document
• QXT QuarkXPress Template
• R# Paradox report format file
• R2D Reflex Analyst, version 2
• RAS Sun rster file uncompressed
• RAW
• REC Windows Recorder macro file
• REG OLE registration database
• RES Windows code resource file
• RLE Windows 3.0, 3.1 and OS/2
• RLE Run Length Encoded BMP file
• RLE Run Length Encoded files from Compuserve
• RLM TIGA firmware code file
• RMI Multimedia data file
• RSL Aldus external resource library
• RTF Microsoft's Rich Text Format
• RXD Reflex Analyst, version 1
• SAM Ami-Pro Professional 2.0, 3.0documents
• SAT Eumetsat Wettersatellitenbild (BTXSAT Austria)
• SC Screen file
• SCD Matrix/Impapro SCODL
• SCR Word capture
• SCR CompuServe Navigator script file/Windows screen saver file
• SCT Scitex CT
• SCx Colorix, Winrix, RIX demo Present
• SEA Compact Pro/Stuffit self-extracting archive
• SES CompuServe Navigator session file
• SET Paradox settings/Norton Desktop desk set files
• SFI SIS Framegrabber
• SGF Starwriter by Star Division Hamburg
• SHH Setup automated settings
• SHW WordPerfect Draw chart galleries
• SHW Screen Show
• SIT Stuffit archive (Macintosh)
• SKD Autosketch Icon
• SLD Slide file format for AUTOCAD
• SLK Multiplan 1.2-4.0
• SLK Microsoft's Symbolic Link format (SYLK)
• SMGL Structured query language ...
• SMM Ami Pro macro file
• SND Sound file
• SOM Paradox sort files
• SPF CompuServe Navigator user-defined script file
• SRC Windows Source file
• SSF Enable 2.0
• SYM Windows symbolic debugging definitions
• SYS DOS system file
• TAR UNIX tape archive file
• TBK ToolBook book file
• TGA Targa file
• TGA TARGA Bitmap for Targa Board
• THD CompuServe message thread file
• THS Thesaurus file
• TIF Tagged Interchange File Format (TIFF)
• TIF TIFF 5.0 Bitmap
• TIF TIFF 2a Standard
• TMP Windows temporary file
• TNY Tiny format ST Atary for PD graphics
• TRM Windows Terminal settings
• TSK Background task application file
• TTF TrueType Font
• TTF TrueType font file
• TUT Tutorial file
• TX8 DOS ASCII-8 text file
• TXT Text
• TXT Text file, ASCII, ANSI or Mac; See also ASC
• UD User-defined file
• UU UUencoded files (Mac, PC or UNIX)
• VAL Paradox validity check file
• VDF Video Display Format
• VI Jovian
• VM Uncompressed files from a Video machine FAST-Electronic
• VOC Creative Labs VOC audio file
• WAV Windows sound file
• WCH WordPerfect on-line coach file
• WCM WordPerfect macro file/Microsoft Works communications file
• WDB Microsoft Works database file
• WFN CorelDRAW font/symbol file
• WIN Windows-created backup files
• WK1 Lotus 1-2-3 Rel. 2
• WK1 Lotus 1-2-3, Version 2, Claris Resolve/Quattro Pro worksheet
• WK3 Lotus 1-2-3, Version 3
• WK3 Lotus 1-2-3 Rel. 3, 3.1
• WKS Lotus 1-2-3 Rel. 1A
• WKS Lotus 1-2-3, Version 1/Microsoft Works spreadsheet
• WMF Windows Metafile Format
• WMF Windows Metafile
• WPD WordPerfect document file/Windows PostScript description file
• WPG WordPerfect Graphic raster graphic files
• WPG WordPerfect Graphics format/DrawPerfect file
• WPP WordPerfect color printing palette
• WPS Microsoft Works word-processing file
• WPT WordPerfect template file
• WR1 Symphony Rel. 1/1. 1/2. 2
• WR1 Lotus Symphony 2.0 worksheet
• WRI Windows Write document
• WRK Symphony Rel. 1, 1.01
• WRK Lotus Symphony 1.2 worksheet
• WS Wordstar file
• XIMB Atari ST Gem graphics format
• XIMG Atari ST GEM
• XLA Microsoft Excel add-on
• XLC Microsoft Excel chart for Windows 3.0, 4.0
• XLM Microsoft Excel macro
• XLS Microsoft Excel spreadsheet
• XLT Microsoft Excel template
• XLW Microsoft Excel workspace
• Z UNIX archive
• ZIP PKZIP-compressed files