Appendix F. Common Filename Extensions

This appendix lists many of the most common filename extensions that you'll find on your system, that you might download, or have sent to you over the Internet.

Extensions were universally used on DOS and Windows 3.1 files, but Microsoft has gone to some difficulty to hide them in Windows XP. This is unfortunate, since they play a major role in the way Windows decides what application will be used to open a file, as well as which files will be visible when opening files in a given application. While direct associations are made between some files without extensions and the applications needed to open them, in most cases, the association is between an extension and a Registry setting that tells the system what application to use. To enable the display of filename extensions, go to Control Panel [Appearance and Themes] Folder Options View tab, and turn off the "Hide extensions for known file types" option.

If you double-click on an unknown file type, the Open With dialog box (see "Folder Options" in Chapter 4) appears, allowing you to make a new association. To subsequently change an association once it has been made, right-click on the file and select Open With, or select Properties and then click Change.

We've tried to list the most common system extensions in Table 1, but there are literally thousands of file formats used by third party applications. And you might be thrown off by an improperly named file, or an application using a standard filename extension for a nonstandard purpose.

Many of these file types can be opened only if you have the appropriate application. However, especially with the growth of the Web, there are often viewers available that allow you to at least view the contents of the file, even if you can't change them. Your web browser and the Windows Picture and Fax Viewer are capable of reading several formats. Paint Shop Pro (http://www.jasc.com) can read and convert nearly any image (graphics) format. And any modern word processor (WordPerfect, Word, etc.) will be able to read just about any text-based document and convert it to a more usable format. If all else fails, you can open just about any file in Notepad; while nontext files will look mostly like jibberish, you may get clues in some of the excerpts of readable text you'll see.

If you still can't find a file's type from it's extension, there are several more good sources:

• Microsoft has put together a simple "extension finder" web site, intended for use with the "Use the Web service to find the appropriate program" feature that appears when you try to open a file with an extension that Windows doesn't recognize. The address for this site is:

  http://shell.windows.com/fileassoc/0409/xml/redir.asp?Ext= {your extension}

• where {your extension} is the filename extension (without the dot) that you wish to learn more about. For example, to find out about the .sit extension, you'd go to:

  http://shell.windows.com/fileassoc/0409/xml/redir.asp?Ext=sit

• Use an ordinary search engine such as Google (http://www.google.com) to search for references to the filename extension. For example, to find out about the .hqx extension, try searching for "hqx file" (with the quotes).

• For more details on dealing with downloads and file formats found on the Net, see Internet in a Nutshell , by Valerie Quercia (O'Reilly). For details on the internals of many graphics file formats, see The Encyclopedia of Graphics File Formats by James Murray and Bill van Ryper (O'Reilly).

Table F-1. Common filename extensions

Extension	Description
.$$$	Temporary file
.1st	ASCII text file (e.g. READ.1ST)
.3ds	3D Studio File
.3fx	CorelChart Effect
.3gr	Windows Video Grabber Data file
.8m	PageMaker Printer font with Math 8 extended character set
.8u	PageMaker Printer font with Roman 8 extended character set
.abf	Adobe Binary Font
.abk	CorelDRAW Automatic backup file
.abm	photo album
.abs	MPEG audio sound file
.aca	Microsoft Agent Character File
.ace	Ace Archiver compressed file
.acf	Microsoft Agent Character File
.ad	AfterDark Screen saver
.adi	AutoCAD Graphics
.adn	Lotus 1-2-3 Add-in
.adx	Archetype Designer Document
.afi	Truevision bitmap graphics
.afm	ATM - many Type 1 font metric ASCII data for font installer
.ai	Adobe Illustrator Vector graphics
.all	WordPerfect for Win General printer information
.alt	WordPerfect Library Menu file
.ans	Ansi graphics; character animation
.aps	MS Visual C++ file
.arc	Compressed file archive
.arf	Automatic Response File
.arj	Compressed file archive created by ARJ
.asc	Ascii text file
.ascx	Microsoft ASP.NET user control file
.asd	Lotus 1-2-3 Screen driver
.asd	Word for Windows Autosave file
.asf	Lotus 1-2-3 Screen font
.asm	Assembly source code file
.asmx	Microsoft .NET Web Service file
.asp	Microsoft Active Server Page
.aspx	Microsoft ASP.NET file
.asx	Microsoft Windows Media Active Stream Redirector file
.asx	Windows Media Streaming video shortcut
.at2	Aldus Persuasion 2.0 Auto template
.atm	Adobe Type Manager data/ info
.au	Audio file used on older web pages
.avi	Video for Windows Audio Video Interleaved movie clip
.awm	Animation Works Movie
.b3d	3D Builder file
.bak	Backup file (generic)
.bas	Basic source code file
.bat	DOS Batch file
.bco	Bitstream Outline font description
.bdr	MS Publisher Border
.bez	Bitstream Outline font description
.bga	Bitmap graphics
.bib	Bibliography (ASCII)
.bin	Binary file
.bit	Bitmap X11
.bk!	WordPerfect for Win Document backup
.bkf	Microsoft Backup File
.bkw	FontEdit Mirror image of font set
.blk	WordPerfect for Win Temporary file
.bm	Bitmap graphics
.bmf	Corel Image file
.bmp	Windows Bitmap
.bpt	CorelDRAW Bitmap fills file
.bsc	MS Fortran Pwbrmake object file
.bup	Backup file (generic)
.c	C source code file
.c++	C++ source code file
.cab	Microsoft installation archive Cabinet File
.cas	Comma-delimited ASCII File
.cc	C++ source code file
.ccb	Visual Basic Animated Button Configuration
.cch	CorelChart Chart
.ccx	Corel PrintHouse file
.cdr	CorelDRAW native format Vector graphics
.cdt	CorelDraw 4.0 Data
.cel	Autodesk Animator - Lumena Graphics
.cfg	Configuration file
.cfl	CorelFLOW Chart
.cgi	Common Gateway Interface script
.cgm	Computer Graphics Metafile vector graphics
.chd	FontChameleon Font descriptor
.chk	ChkDsk Recovered data
.chk	WordPerfect for Win Temporary file
.cif	Caltech Intermediate Format graphics
.cif	Easy CD Creator CD Image File
.clp	Quattro Pro Clip art graphics
.cls	C++ class definition file
.cmf	Creative Music File FM-music file
.cmp	CorelDRAW Header file for PostScript printer files
.cmp	MS Word for DOS User dictionary
.cmv	CorelMove CorelDraw 4.0 Animation
.cnt	Helpfile contents
.cnv	Word for Windows Data conversion support file
.cnv	WordPerfect for Win Temporary file
.col	Autodesk Animator - many Color palette
.col	MS Multiplan Spreadsheet
.cph	Corel Print House image
.cpi	Colorlab Processed Image bitmap graphics
.cpi	DOS Code Page Information file
.cpp	C++ source code file
.cps	Colored postscript files
.cpx	Corel Presentation Exchange Compressed Drawing
.crf	MS MASM - Zortech C++ Cross-reference
.crs	WordPerfect 5.1 File Conversion Resource
.csv	Comma Separated Values text file format (ASCII)
.ctx	Microsoft online guides Course TeXt file
.ctx	Pretty Good Privacy RSA System Ciphertext file
.cvp	WinFax Cover page
.cvs	Canvas Graphics
.dat	Data file (generic)
.dbg	MS C/C++ Symbolic debugging information
.dcr	Shockwave file
.dcs	CYMK format Bitmap graphics
.ddb	Bitmap graphics
.dev	Device driver (old)
.dfv	Word Printing form
.dib	Device-Independent Bitmap Bitmap graphics
.dic	Lotus Notes / Domino dictionary file
.dip	Graphics
.dis	CorelDraw Thesaurus
.diz	Description In Zip Description file
.dld	Lotus 1-2-3 Data
.dlg	MS Windows SDK Dialog resource script file
.dll	CorelDRAW Export/import filter
.doc	Microsoft Word Document
.dot	CorelDRAW Line-type definition file
.dot	Word for Windows Template
.drs	WordPerfect for Win Display Resource
.drv	Device driver (old)
.dsr	WordPerfect for Win Driver Resource
.dvc	Lotus 1-2-3 Data
.dvp	AutoCAD Device parameter file
.dwg	AutoCAD Drawing database
.dxf	AutoCAD Drawing Interchange File Format vector graphics
.dyn	Lotus 1-2-3 Data
.eeb	WordPerfect for Win Button bar for Equation Editor
.emf	Enhanced Metafile graphics
.eml	MS Outlook Express Electronic Mail
.end	CorelDRAW Arrow-head definition file
.env	WOPR Enveloper macro
.env	WordPerfect for Win Environment file
.eps	Adobe Illustrator Encapsulated PostScript vector graphics
.eqn	WordPerfect for Win Equation
.evt	Event log
.evy	WordPerfect Envoy Document
.exe	Executable program
.f77	Fortran 77 source code file
.faq	Frequently Asked Questions text file
.fax	Incoming Fax
.fd	MS Fortran Declaration file
.feb	WordPerfect for Win Button bar for Figure Editor
.ff	Agfa Compugraphics Outline font description
.ffl	Microsoft Fast Find File
.ffo	Microsoft Fast Find File
.ffx	Microsoft Fast Find File
.fh3	Aldus FreeHand 3.x Vector graphics
.fh4	Aldus FreeHand 4.x Vector graphics
.fi	MS Fortran Interface file
.fif	Fractal Image Format file
.fil	WordPerfect Overlay
.flc	Autodesk Animator Animation
.fli	Autodesk Animator Animation
.flm	AutoCAD/AutoShade Film Roll
.fm	FrameMaker Document
.fm1	Lotus 1-2-3 release 2.x Spreadsheet
.fm3	Lotus 1-2-3 release 3.x Spreadsheet
.fmb	WordPerfect for Win File Manager Button bar
.fnt	Font file
.fon	Windows 3.x font library Font file
.fot	Windows Font Installer Installed Truetype font
.frf	FontMonger Font
.frm	Visual Basic Form
.frs	WordPerfect for Win Screen Font Resource
.fsx	Lotus 1-2-3 Data
.fts	Windows Help Full-Text Search Index file
.fxs	WinFax Fax Transmit Format graphics
.gcd	Graphics
.gly	MS Word Glossary
.gph	Lotus 1-2-3/G Graph
.gwi	Groupwise File
.gz	GNU zip Compressed file archive created by GZIP
.h	Header file (used with .c source code)
.h++	C++ Header file
.hdf	Help Development Kit Help file
.hdx	AutoCAD - Zortech C++ Help index
.hgl	Hp Graphics Language graphics
.hh	C++ header file
.hlp	Help information
.hpf	PageMaker Hp LaserJet fonts
.hpg	AutoCad - Harvard Graphics HPGL plotter file vector graphics
.hpj	MS Help Compiler Help project
.hqx	Compressed Macintosh file archive created by Binhex
.htm	HyperText Markup Language document
.html	HyperText Markup Language document
.htt	Hypertext template
.hwd	Hollywood Presentation
.hxx	C++ header file
.hyc	WordPerfect Data
.hyd	WordPerfect for Win Hyphenation dictionary
.icb	Bitmap graphics
.icn	Icon source code file
.ilk	MS ILink incremental linker Outline of program's format
.imp	Lotus Improv Spreadsheet
.imz	Compressed floppy image
.inc	Include file (programming)
.inf	Information text file
.inf	Install script / Driver information
.ini	Initialization file
.ink	CorelDRAW Pantone reference fills file
.ins	WordPerfect Data
.ion	File description (e.g., descript.ion )
.ipl	CorelDRAW Pantone Spot reference palette file
.irs	WordPerfect Resource
.isr	MS Streets & Trips Route file
.jar	Java archive file
.jas	Graphics
.jav	Java source code file
.jff	JPEG File Interchange Format Bitmap graphics
.jpg	JPEG Image File
.jsp	Java Server page
.jtf	JPEG Tagged Interchange Format Bitmap graphics
.kar	Midi file with karaoke word track
.key	Keyboard macros
.lbm	DeluxePaint Bitmap graphics
.lbr	Lotus 1-2-3 Display driver
.lcn	WordPerfect Lexicon
.ldb	MS Access Data
.lex	Lexicon
.lha	Compressed file archive created by LHA/LHARC
.lib	Library file (programming)
.lif	Compressed file archive
.lin	AutoCAD Line types
.lnk	Windows Shortcut
.log	Log file (ASCII)
.lrf	MS C/C++ Linker response file
.lrs	WordPerfect for Win Language Resource File
.lsl	Lotus Script Library
.ltm	Lotus Forms Form
.lwz	MS Linguistically Enhanced Sound File
.lzh	Compressed file archive created by LHA/LHARC
.lzs	Compressed file archive created by LARC
.lzx	Compressed file archive
.mak	Makefile
.mak	Visual Basic Project file
.man	Command manual
.map	Color palette
.map	Linker map file
.mat	Matlab Data file
.mbx	Eudora Mailbox
.mda	MS Access Data
.mdb	MS Access Database
.mdl	3D Design Plus Model
.mdt	MS ILink incremental linker Data table
.me	ASCII text file (e.g., READ.ME )
.meb	WordPerfect Library Macro Editor bottom overflow file
.med	WordPerfect Library Macro Editor delete save
.mem	WordPerfect Library Macro Editor macro
.meq	WordPerfect Library Macro Editor print queue file
.mer	WordPerfect Library Macro Editor resident area
.mes	WordPerfect Library Macro Editor work space file
.met	WordPerfect Library Macro Editor top overflow file
.mex	WordPerfect Library Macro Editor expound file
.mht	MS MHTML Document
.mic	Microsoft Image Composer file
.mif	FrameMaker Maker Interchange Format
.mim	MIME file (used for email attachments)
.mk	Makefile
.mke	MS Windows SDK Makefile
.mmf	MS Mail Mail message file
.mnd	AutoCAD Menu Compiler Menu source
.mnx	AutoCAD Compiled menu
.mny	MS Money Account book
.mov	AutoCAD AutoFlix Movie
.mp2	Mpeg audio or video file
.mp3	MPEG Layer 3 Audio file
.mpc	MS Project Calender file
.mpd	MS Project database file
.mpg	Mpeg movie
.mpm	WordPerfect Library Mathplan macro
.mpp	MS Project Project file
.mpv	MS Project View file
.mrb	MS C/C++ Multiple Resolution Bitmap graphics
.mrs	WordPerfect for Win Macro Resource file
.msc	MS C makefile
.msi	Windows Installer file
.mso	MS FrontPage file
.msp	Microsoft Paint Bitmap graphics
.mst	MS Windows SDK Setup script
.msw	MS Word Text file
.mu	Quattro Pro Menu
.mvf	AutoCAD AutoFlix Stop frame file
.mvi	AutoCAD AutoFlix Movie command file
.mxt	MS C Data
.nfo	Info file (ASCII)
.nlm	Netware Loadable Module
.nsf	Lotus Notes / Domino database
.nt	Windows NT Startup files
.ntf	Lotus Notes / Domino template file
.nws	Info text file
.nxt	NeXT format Sound
.ofm	Adobe font
.oft	MS Outlook Item Template
.old	Backup file (generic)
.org	Lotus Organizer Calendar file
.ost	Microsoft Outlook Offline file
.out	Output file (ASCII)
.p65	Adobe PageMaker v6.5
.pab	Microsoft Outlook personal address book
.pak	Compressed file archive created by PAK
.pal	Color palette
.pas	Pascal source code file
.pat	AutoCAD - Photostyler Hatch patterns
.pat	CorelDRAW Vector fill files
.pb	WinFax Pro Phonebook
.pbi	MS Source Profiler Profiler Binary Input
.pbm	Portable Bit Map graphics
.pbo	MS Source Profiler Profiler Binary Output
.pbt	MS Source Profiler Profiler Binary Table
.pcc	PC Paintbrush Cutout picture vector graphics
.pcd	Kodak PhotoCD Graphics
.pcf	MS Source Profiler Profiler Command File
.pch	MS C/C++ Precompiled header
.pcl	HP Printer Control Language HP-PCL graphics data
.pcx	PC Paintbrush Bitmap graphics
.pda	Bitmap graphics
.pdd	Adobe PhotoDeluxe Image
.pdf	Adobe Portable Document Format
.peb	WordPerfect Library Program Editor bottom overflow file
.ped	WordPerfect Library Program Editor delete save
.pem	WordPerfect Library Program Editor macro
.peq	WordPerfect Library Program Editor print queue file
.per	WordPerfect Library Program Editor resident area
.pes	WordPerfect Library Program Editor work space file
.pet	WordPerfect Library Program Editor top overflow file
.pfb	Type 1 font file
.pfm	Type 1 font metric file
.pgm	Portable Grayscale bitMap graphics
.pgp	Pretty Good Privacy RSA System Support file
.ph	MS C/C++ Phrase-table
.ph	Perl header file
.pic	PC Paint Bitmap graphics
.pka	Compressed file archive created by PKARC
.pkg	NeXT Installer script
.pl	Perl source code file
.pl1	3D Home Architect Room plan
.pln	WordPerfect for Win Spreadsheet
.plt	AutoCAD Hpgl plotter file vector graphics
.pm3	PageMaker 3 Document
.pm4	PageMaker 4 Document
.pm5	PageMaker 5 Document
.png	Portable Network Graphics Bitmap
.pnm	Graphics file (Portable aNy Map)
.pov	Persistence Of Vision Raytraced graphics image
.ppb	WordPerfect for Win Button bar for Print Preview
.ppd	Acrobat PostScript Printer Description
.ppm	Portable Pixel Map graphics
.pr2	Aldus Persuasion 2.x Presentation
.pr3	Aldus Persuasion 3.x Presentation
.prc	Palm Pilot resource file
.prj	Project
.prn	Lotus 1-2-3 - Symphony Text file
.prs	WordPerfect for Win Printer Resource (e.g., fonts)
.ps	Postscript file
.psd	Photoshop Image
.pst	Microsoft Outlook personal folder
.pt3	PageMaker 3 Template
.pt4	PageMaker 4 Template
.pub	MS Publisher Page template
.pub	Pretty Good Privacy RSA System Public key ring file
.pwl	Password List
.py	Python script file
.pyc	Compiled PYTHON script file
.qbw	QuickBooks for Windows Spreadsheet
.qdat	Quicktime Installer Cache
.qdb	Quicken data file
.qdf	Quicken for Windows data file
.qdt	Quicken data file
.qfl	Quicken Family Lawyer file
.qfx	QuickLink Fax
.qic	Backup set for Microsoft Backup
.qif	Quicken Interchange Format
.qlb	MS C/C++ Quick library
.qlp	QuickLink Printer driver
.qrs	WordPerfect for Win Equation Editor support file
.qt	Quicktime movie
.qxd	QuarkXPress Document
.qxl	QuarkXPress Element library
.r00, .r01	Compressed file archive created by RAR (supplemental to . rar )
.ra	RealMedia file
.ram	RealMedia shortcut
.rar	Compressed file archive created by RAR
.ras	Sun Rasterfile graphics
.rc	MS C/C++ - Borland C++ Resource script
.rcg	Netscape newsgroup file
.rdp	Remote Desktop Connection Profile
.ref	Cross-reference
.reg	Corel programs Registration
.res	MS C/C++ - Borland C++ Compiled resource
.ri	Lotus 1-2-3 Data
.rib	3DReality Graphics in Renderman format
.rif	Fractal Design Painter Riff bitmap graphics
.rl4	Bitmap graphics
.rl8	Bitmap graphics
.rlc	Graphics 1bit/pixel scanner output
.rnd	AutoCAD AutoShade Rendering Slide
.rs1	Route 1 Pro Script
.rtf	Windows Word Rich Text Format text file (Word)
.rtf	Windows Help file script
.rvp	MS Scan Configuration file
.sav	Configuration file
.sav	Backup file
.sbi	Creative Labs Sound Blaster Instrument file
.sco	High score
.sdf	System Data Format (ASCII)
.sea	Self-Extracting compressed Macintosh file Archive
.sec	Pretty Good Privacy RSA System Secret key ring file
.sfi	HP LaserJet landscape Printer font
.shb	CorelShow Background
.shm	WordPerfect Library Shell macro
.shp	AutoCAD Shape file and source file for text fonts
.shw	WordPerfect Presentations Slide show
.shx	AutoCAD Shape entities
.sif	Windows NT Setup Setup Installation Files info
.sit	Compressed Macintosh archive created by STUFFIT
.slb	AutoCAD Slide library
.sld	AutoCAD Slide
.sng	midi sound Song
.som	Quattro Pro Network serial numbers
.spc	MS Multiplan Program
.spc	WordPerfect for Win Temporary file
.spm	WordPerfect wp{wp}.spm Data
.srp	QuickLink Script
.ssm	RealPlayer Standard Streaming Metafile
.sts	MS C/C++ Project status info
.sup	WordPerfect for Win Supplementary dictionary
.svd	MS Word Autosave file for document
.svg	MS Word Autosave file for glossary
.svs	MS Word Autosave file for stylesheet
.swf	ShockWave Flash object
.syn	MS Word 5 Synonym file
.sys	DOS System file - device driver or hardware configuration info
.tar	Compressed file archive created by TAR
.taz	Compressed file archive created by TAR and COMPRESS (equiv. to . tar.Z )
.tga	Truevision Targa bitmap graphics
.tgz	Compressed file archive created by TAR and GNUzip (equiv. to . tar.gz )
.thm	Microsoft Clipart Gallery database
.ths	WordPerfect for Win Thesaurus dictionary
.tif	Tagged Image File Format bitmap graphics
.tis	MahJongg 3.0 Tile set
.tlb	Visual C++ Type library
.tmf	WordPerfect for Win Tagged Font Metric file
.tmp	Temporary file
.toc	Eudora Table Of Contents
.tpz	Compressed file archive created by TAR and GNUzip (equiv. to . tar.gz )
.trn	Quattro Translation support file
.tst	WordPerfect for Win Printer test file
.ttf	Truetype Font file
.txt	Text file
.tym	PageMaker 4 Time Stamp
.tz	Compressed file archive created by TAR and COMPRESS (equiv. to . tar.Z )
.uhs	Universal Hint System
.uif	WordPerfect for Win Long prompts for windows
.uu	Compressed ASCII file archive created by UUEncode/UUDecode
.uue	Compressed ASCII file archive created by UUEncode/UUDecode
.vbs	Visual Basic Visual Basic Script file
.vbx	Visual Basic Visual Basic eXtension (custom control)
.vcf	VCard file
.vcw	MS Visual C++ Visual workbench information
.vda	Bitmap graphics
.vmc	Acrobat reader Virtual memory configuration
.vnc	VNC connection profile
.voc	Creative Voice file Digitized samples
.vrm	QuattroPro Overlay file
.vrs	WordPerfect Video Resource (e.g., video device driver)
.vue	3D Studio Animation
.vxd	Virtual device driver
.wab	Outlook (Windows Address Book) File
.wad	Doom Game File
.wav	Waveform audio file
.wb1	Quattro Pro Notebook
.wb2	Quattro Pro Spreadsheet
.wba	Winace Zip file
.wba	WindowBlinds Compressed Skin for Windows XP
.wbk	WordPerfect for Win Document/workbook
.wcd	WordPerfect for Win Macro token list
.wcm	MS Works Data transmission file
.wcm	WordPerfect for Win Macro
.wcp	WordPerfect for Win Product information description
.wdb	MS Works Database
.wdl	Windows XP Watchdog Log file
.wfn	CorelDRAW Font
.wfx	WinFax Data file
.wg1	Lotus 1-2-3/G Worksheet
.wg2	Lotus 1-2-3 for OS/2 Worksheet
.wiz	MS Publisher Page wizard
.wk1	Lotus 1-2-3 version 2.x - Symphony 1.1+ Spreadsheet
.wk3	Lotus 1-2-3 version 3.x Spreadsheet
.wk4	Lotus 1-2-3 version 3.4 Spreadsheet
.wkb	WordPerfect for Win Document
.wke	Lotus 1-2-3 educational version Spreadsheet
.wkq	Quattro Spreadsheet
.wks	Lotus 1-2-3 version 1A - Symphony 1.0 - MS Works Spreadsheet
.wma	Microsoft Windows Media Active Streaming file
.wmc	WordPerfect for Win Macro file
.wmf	Windows MetaFile vector graphics
.wmv	MS Active Streaming file
.wn	NeXT WriteNow Text
.wnf	CorelDRAW native format Outline font description
.wp	WordPerfect 4.2 Text file
.wp5	WordPerfect 5.x Document
.wpd	WordPerfect 6.0 - PFS:WindowWorks Document
.wpf	WordPerfect Form
.wpg	DrawPerfect WordPerfect Graphics vector graphics
.wpk	WordPerfect for Win Macros
.wpm	WordPerfect Macros
.wps	MS Works Text document
.wq!	Quattro Pro Compressed spreadsheet
.wq1	Quattro Pro Spreadsheet
.wri	Windows Write Text file
.wrl	VRML file
.wrml	VRML file
.wrs	WordPerfect for Win Windows Resource (e.g., printer driver)
.wsz	WinAmp Skin Zip file
.wwb	WordPerfect for Win Button bar for document window
.wwk	WordPerfect for Win Keyboard layout
.xla	MS Excel Add-in macro sheet
.xlb	MS Excel Data
.xlc	MS Excel Chart document
.xll	MS Excel Excel Dynamic Link Library
.xlm	MS Excel Macro sheet
.xlr	MS Works file
.xls	MS Excel Worksheet
.xlt	Lotus 1-2-3 - Symphony - Procomm Plus Translation table
.xlt	MS Excel Template
.xlw	MS Excel Workbook
.xmi	Compressed extended midi music
.xnk	Microsoft Exchange Shortcut
.xwk	Crosstalk Keyboard mapping
.xwp	Crosstalk Session
.z	Compressed file ASCII archive created by COMPRESS
.z3	Infocom game module
.zip	Compressed ZIP file archive
.zoo	Compressed file archive created by ZOO