.??_  Files ending in "_" are often compressed install files of the same
          name (e.g., .EX_ expands to .EXE, .DL_ expands to .DLL, etc.)
  .D    Dialect Source Code File
        D Programming Language Source Code File
  .D_1  Polytext Ma'archot Meida Co. S"TaM ("Sifriyah Toranit M'muchshevet" - Computerized Torah Library)
  .D_3  Polytext Ma'archot Meida Co. S"TaM ("Sifriyah Toranit M'muchshevet" - Computerized Torah Library)
  .D$W  MindStor Driver (digital wallet)
  .D00  Ganbatte! Winamp Plug-in
  .D01  Ganbatte! Winamp Plug-in
          Note: .D00 and .D01 formats created by Jens-Christian Huus
                of the Vibrants and contains OPL2 music data.
  .D11  Macro Mania Data File
  .D2D  3D Fassade Plus 2D/3D Object File
  .D2I  Shadowmaster Diablo II LOD Character Editor File
  .D2S  Diablo II Character and Equipment File
  .D2V  DVD Ripper File
  .D3D  CorelDream 3D File
        Direct3D File
  .D3F  MS MechCommander 2 Encyclopedia
  .D64  Commodore 64 Emulator Disk Image
  .D8A  AmBiz Productivity Pak Catalog
  .DAD  Chromeleon Channel Raw Data
  .DAF  OM2 911 Xchange Version 3 & 6 Document
  .DAN  ATI Radeon Video Driver File
  .DAO  Windows Registry Backup
        IsoBuster File
  .DAP  Omnis5 Application File
        MS Access Data Access Page [Buy Office XP at Shop.Microsoft]
  .DARBY  TheWord & Bible Companion Darby's Bible Translation Bible
  .DAT  Data (multiple programs)
          Note: RDXR020305.DAT is Morpheus adware. Kill this and others with Ad-aware.
        WordPerfect Merge Data
        (also possibly) MPEG File
        Mitsubishi DJ-1000 and Photorun Native Format
        Gunlok Archive  [Dragon UnPACKer]
        Nascar Racing Archive  [Dragon UnPACKer]
        SPOT Graphic  [XnView]
        SHARP MZ-series Emulator RAM-Disk File
  .DAWN  Experimental File Format (.DAWN)
  .DAZ  Poser 3D File
  .DB   Paradox Database
        Progress Database
        Solid Database
        WindowsXP Thumbnail Database
        ANSYS Database
        SmartWare Office Pac File (requires login)
        Oracle Database
  .DB$  dBASE Temporary File
        Clarion Modula-2 Debug Info
  .DB2  dBase II File
  .DB3  dBASE III File
  .DBA  DataEase Data File
        DarkBASIC File
  .DBB  ANSYS Database Backup
        Mopheus Music File
  .DBC  MS Visual Foxpro Database Container
        PROGNOSIS Database Collection Document File
  .DBD  Clarion Modula-2 Debug Info
        Business Insight Data
        Oracle Record Type
  .DBF  Database (multiple programs) [started as dBASE] [File Structure]
        Oracle 8.x Tablespace File
        ArcView Shape File (GIS-related file)
  .DBG  MS C++ Symbolic Debugging Info
        Oracle Generator File
  .DBI  Photo Soap2 File
  .DBK  dBase Database Backup
        Orcad Schematic Capture Backup File
  .DBL  WindowsXP Product Activation File (if on WPA.DBL in the System32 folder)
  .DBM  Cold Fusion Template
        DataBoss Menu Template
        DataEase Data File
        OzWin CompuServe E-mail/Forum Access SYSOP File
  .DBO  dBase IV Compiled Program File
  .DBOOK  Pocket Diary Text
  .DBQ  Paradox Memo
  .DBR  Comdial VMMI Database
  .DBS  SQL Format Database
        Word Printer Description File
  .DBT  Database Text File [dBASE] [File Structure]
        Oracle Template
        Foxbase Memo
  .DBV  Flexfile Memo Field File
  .DBW  DataBoss Database File
  .DBX  Database (multiple programs)
        DataBeam Image
        MS Visual Foxpro Table
  .DC   DesignCAD CAD File
  .DC2  DesignCAD CAD File
        Kodak DC25 Digital Camera File
        DC2-PC Motion Control Command Language File
  .DC5  DataCAD Drawing File
  .DCA  Visual Basic Active Designer Cache
        IBM DisplayWrite Document Content Architecture Text File
        D-PAS Portfolio Manager File [Education about D-PAS]
  .DCB  Concordance Database Control Block
  .DCD  Document Content Description File
        FORTRAN Data File  [FORTRAN]
        INMOS Transputer Development System Occam Object Code
  .DCF  Design Rule for Camera File Systems File
        DynSite Configuration File
        Dyadic Data File
        Disk Image File
  .DCL  DumpSec
        DesignComposer Addition to Layout Knowledge Base
  .DCLST  DC and DC++ Direct Connect [File sharing network using DC++]
  .DCM  DCM Module Format
        Dicom  [XnView]
  .DCP  Delphi Compiled Packages
        OS/2 Data CodePage
  .DCR  Shockwave File
        Kodak Proprietary Image Format
  .DCS  Quark Desktop Color Separation Specification
        ACT! Activity Data File
  .DCT  Dictionary (various)
        MS Visual Foxpro Database Container
  .DCU  Delphi Compiled Unit
  .DCV  DriveCrypt Volume
  .DCW  Draft Choice for Windows
  .DCX  FAX Image  [IrfanView]
        ElectraSoft Fax
        PC-Paintbrush File [SwiftView]
        Bitmap Graphics  [IrfanView]
        MS Visual Foxpro Database Container
  .DD   Macintosh Compressed Disk Doubler Archive
        C64 Doodle  [XnView]
  .DDB  Device-Dependent Bitmap Graphics File
        Design Database File (database definition file) [MS Access???]
        INMOS Transputer Development System Occam Debugging Info
        Protel 99SE Design Database File
  .DDATA  Pocket Diary Text File
  .DDE  Dynamic Data Exchange
  .DDF  BTRIEVE Data Dictionary File (allows other programs to access data)
        Bitstream Fontware File
        Doom Definition File
        Music Library File
  .DDI  DiskDupe Image
        Disk Doubler Image
  .DDL  MS Data Definition Language File (SQL Server Query Analyzer)
  .DDM  Intelliware Data Modeller (Data Mapping and Aliasing)
  .DDP  OS/2 Device Driver Profile File
        Delphi 6 File
  .DDS  INMOS Transputer Development System Occam Compiler Descriptor
        Photoshop Compressed Textures
  .DDX  Juno "Get" File
        Device Data Exchange Format File (text CAD design exchange format)
  .DDW  CSPro File (combined IMPS and ISSA Census Processing System)
  .DE   MetaProducts Download Express Incompletely Downloaded File
  .DEB  DOS Debug Script
        Debian Linux Package
  .DEC  VersaPro Declaration File
  .DESK  Card Deck File
  .DESKLINK  MS Windows Explorer Desktop Controls
  .DEF  Definitions
        SGML Tag Definition
        Modula-2 Definition Module File
        SmartWare II Data File
        C++ Definition
        3D Fassade Plus Define Module File
        Geoworks Assembly Header File
  .DEI  Gerber Design Engineered Interface
  .DEL  Data
  .DEM  Descent Demonstration
        USGS Map
        Digital Elevation Model File (GIS-related file)
        Half-life Game File
  .DEP  Setup Wizard Dependency
  .DEPLOY  DeployMaster Setup Script
  .DER  Certificate File
  .DES  Description Text
        Tribes 2 Game File
        Quickbooks Template
        Pro/DESKTOP File
        Interscope BlackBox File (encryption program)
  .DEU  ATI Radeon Video Driver File
  .DEV  Device Driver
        Device Independent TeX
        LaTeX File
  .DEX  WinGlucofacts File (diabetes management software)
  .DEZ  DES Encrypted Zip File
  .DF   Lightscape Parameters
  .DF1  Omnis7 and Omnis Studio Database File (also .DF2, .DF3, etc.)
  .DFC  Voicemail File (Trio Voice Communications and maybe others)
  .DFD  File Flow Diagram Graphic
  .DFF  Digital Animation Format
        Grand Theft Auto 3 Export Format
  .DFI  Digifont Outline Font Description
  .DFL  Signature Default Program Settings
  .DFM  Borland C++ Builder 6 Form
        Borland Delphi Form
        File Flow Diagram Model
  .DFP  Stabilogram Diffusion Analysis File (Requires MatLab)
        Digital Fusion Plug-in
  .DFS  Delight Sound File
  .DFT  Fakt2000 File
        SolidEdge CAD File
        Workshare Synergy File
        PC Draft File
  .DFV  Word Print Format Template [Buy Office XP at Shop.Microsoft]
  .DG   Autotrol Graphics
  .DGC  TurboTax-related File
  .DGK  Delcam Powershape/Powermill (3D CAD)
  .DGN  Microstation CAD Drawing File
        Intergraph Graphics
        Dragon 32 Emulator
  .DGO  Dimitrius Settings File (Dimitrius is program author)
  .DGR  Fax Page (MS Outlook Express)
        DART Pro 98 File Group Details
        Keeptool ER Diagrammer
  .DGS  AT Advanced Diagnostics File
  .DH   Geoworks Dependency Information File
  .DHE  MS Help Workshop Dialog Box Help Editor Document
  .DHP  Dr. Halo PIC
  .DHT  Gauss Data File
  .DIA  Computer Support Corp Diagraph Graphics File
        DIA Drawing
  .DIB  Device-Independent Bitmap Graphic  [IrfanView]
  .DIC  Dictionary (various)
  .DIF  Data Interchange Format
        DIFF Command Output (patch script)
  .DIG  Text Document
        Digilink Format
        Sound Designer Audio File
  .DIL  DesignComposer Input DIL Script
  .DIN  DataEase File
        ADC Labs eWave File (broadcast automation software)
  .DIP  Graphics File
  .DIR  Procomm Plus Dialing Directory
        Macromedia Director File
        DEC VAX Directory
        Worms Armageddon Archive  [Dragon UnPACKer]
  .DIS  DKB Ray Tracer File  [XnView]
        DATAIR Data Import Specification Layout File
        VAX Mail Distribution File
        Corel Draw Thesaurus
  .DISCO  MS .NET Web Service Discovery File
  .DIT  MS Win2000 Active Directory Schema
  .DIVX  Movie Encoded with DivX-codec
  .DIZ  Description In Zip File
  .DJE  MattBatt iAM-player
  .DJV  DjVu File  [XnView]
  .DJVU  DjVu File  [XnView]
  .DKB  DKBTrace Ray-Traced Graphics File
  .DL   Animation File (this appears to be associated with glifomon.zip, a probable porno file)
        Masked .DLL File (often used by malware to hide .DLL files from virus scanners [e.g., Sub7])
  .DL_  Compressed .DLL File in an Install Archive
  .DL4  Lindab Dimsilencer File
  .DLC  Echelon HQ Configuration File
        Model Dislocation File
        3D Studio Max Animation Controller File (Character Studio)
  .DLD  Lotus File
  .DLE  Macromedia Designer 3D Translator File (Also 3D Studio Max)
  .DLF  Belkin Router Firmware Update
  .DLG  Dialog Resource Script
        C++ Dialogue Script
        Infinity Engine Game Dialog File
        Digital Line Graph (U.S. Geological Survey geographic database)
  .DLK  INMOS Transputer Development System Occam Compiler Link Info
  .DLL  Dynamic Link Library
        CorelDraw Export/Import Filter
  .DLM  Dirty Little Helper Cheat File
        Dynamic Link Module
        ASCII Delimited File (sometimes used in voting systems)
        3D Studio Max Character Studio
  .DLS  Downloadable Sounds (Interactive Music Architecture)
        Norton DiskLock Setup File
        ADAPTA DLS/32 Supply Chain Planning (ASCII file with general number data)
        dataLive Database Engine File
  .DLU  Dirty Little Helper Update File
  .DM2  Quake 2 Demo File  [Viewer]
  .DM3  Quake 3 Arena Demo File  [Viewer]
  .DM_48  Quake 3 Arena Demo File  [Viewer]
  .DM_57  Return to Castle Wolfenstein Demo File [Download site]
  .DM_59  Return to Castle Wolfenstein Demo File [Download site]
  .DM_66  Quake 3 Arena Demo File  [Viewer]
  .DM_67  Quake 3 Arena Demo File  [Viewer]
  .DMC  Medical Manager DML System Compiled Script
  .DMD  Visual dBASE Data Module
        dB2K/dQuery Web DataModule
        OS/2 Warp Device Manager Driver
  .DME  Medical Manager DML System Data Merge
  .DMF  Delusion/XTracker Digital Music File
        Packed Amiga Disk Image
  .DMG  Macintosh OS X Disk Image File (Treated like a real disk)
  .DMK  Digimask File (3D human faces)
  .DML  Darn! Shopping! Mall File
        Medical Manager DML System Script
  .DMO  Derive Demo
  .DMP  Dump (various)
        INMOS Transputer Development System Occam Core Dump
  .DMS  Amiga DISKMASHER Compressed Archive (see ADF) [Amiga Forever]
  .DMT  Delcam Machining Triangles (3D CAD)
  .DMX  Medical Manager DML System Index for Custom .DME Files
        ProTrader Database
  .DN8  Blue Martini UTF-8 Encoded DNA File (eCRM)
  .DNA  Blue Martini DNA File (eCRM)
  .DNA.XML  Blue Martini XDNA File (eCRM)
  .DNC  Machine Tool Communications
  .DND  ClustaW Tree File
  .DNE  Darn v5+ (Windows) Events List
        Netica Bayes Net File
  .DNG  Dungeon File (created by ID software)
  .DNI  realMyst 3D Archive  [Dragon UnPACKer]
  .DNL  DigitalWebBook Electronic Book (requires installation of DigitalWebBook plug-in)
        netMod Modem Firmware Upgrade File
  .DNS  DynSite Plug-in File
  .DO   Stata Batch Analysis File
        DigitalOutrage Hosting Control Panel Info
  .DOB  User Document Form File
  .DOC  Document or Documentation (many programs/formats)
        MS Word Document [Buy Office XP at Shop.Microsoft]
        DisplayWrite 4 File
  .DOCHTML  MS Word HTML Document [Buy Office XP at Shop.Microsoft]
  .DOCMHTML  MS Word HTML Document [Buy Office XP at Shop.Microsoft]
  .DOF  Racer 3D Geometry File
  .DOG  Laughing Dog Screen Saver
  .DOH  Geoworks Dependency Information File
  .DOL  D-PAS Portfolio Manager Flexible Benchmarking Analysis File [Education about D-PAS]
  .DOO  Atari Doodle  [XnView]
  .DOP  Digital Orchestrator File
  .DOQ  Digital Orthophoto Quadrangle (digital aerial photo)
  .DOQQ  Digital Orthophoto Quarter Quadrangle (smaller digital aerial photo)
  .DOS  Text File/DOS Specification Info
        1st Reader External Command File
        Network Driver File
  .DOT  MS Word Document Template [Buy Office XP at Shop.Microsoft]
        Corel Lines-Definition
  .DOTHTML  MS Word HTML Document Template [Buy Office XP at Shop.Microsoft]
  .DOX  Text File
        MultiMate Document
        User Document Binary Form File
  .DOZ  VENDINFO Description Out of Zip File
  .DP   Daily Planner Calendar File
        DataPhile Data File
  .DPA  Serif DrawPlus Animation
  .DPC  DiscPlay Collection File
        Delphi Package Collection File
  .DPJ  DeskProto CAM Project File
  .DPK  Delphi Package File
  .DPL  Borland Delphi 3 Packed Library
        Digital Photo Librarian Database
  .DPP  Serif DrawPlus Drawing
  .DPR  Borland C++ (or Delphi) Default Project
  .DPS  DivX XP Skin (.ZIP file format)
  .DPT  Publish-It! Publication File
  .DPX  Digital Moving Picture Exchange  [XnView]
  .DPY  Realpolitik Saved Game
        PROGNOSIS Display Document File
  .DQA  itaz doQument File
  .DQB  D-PAS Portfolio Manager File [Education about D-PAS]
  .DQD  itaz Default doQument Database
  .DQY  MS Excel ODBC Query File [Buy Office XP at Shop.Microsoft]
  .DR9  Directory File
  .DRC  Orcad Schematic Capture Design Rules Check Report File
        DriveCrypt Container File (Note: This extension was changed to .DCV due to a WinXP conflict.)
        Borland Delphi Compiled Resource File
  .DRES  Diagnosis Results
  .DRJ  Deraj Data File
  .DRL  DocObject Resource Locator
  .DRM  Steinberg Cubase Drum File
  .DRN  Darn for DOS
  .DRS  WordPerfect Driver Resource
        Age of Empires 2 Archive  [Dragon UnPACKer]
  .DRV  Device Driver
  .DRW  Drawing (various)
        Micrografx Vector Graphic
        Pro/E Drawing
  .DRX  Adobe Photoshop Tutorial
  .DRZ  Draz Paint  [XnView]
  .DS   Chemisty Software
        PhotoMax Drive
        HP Officejet T Series All-in-One TWAIN File
  .DS4  Micrografx Designer Graphics (ver 4)
  .DSA  DasyTec DASYLab File
  .DSB  DasyTec DASYLab File
  .DSC  Oracle Discard File
        Nikon Coolpix Disk Identification File
        dpkg-source (info needed help unpack Debian source archives)
  .DSCE  Diagnosis Scenario
  .DSD  DataShaper Database File
        Document Structure Definition File
  .DSES  Diagnosis Session
  .DSF  Micrografx Designer
        PC-TRUST Document Signer (Extension means file is signed)
        Delusion/XTracker Digital Sample
  .DSG  Doom Saved Game
  .DSH  Dashboard PDA Wallpaper
  .DSI  Digital Sound Module Tracker Format (unverified)
        R-Studio Hard Disk Scan Results File
  .DSK  Borland C++ or Turbo Pascal Project Desktop File
        Novell Driver File
        Lotus Notes Design Elements
        SHARP MZ-series Emulator File
  .DSL  Lingvo User Feature Dictionary
  .DSM  Delphi Symbol File
        Digital Sound Module Tracker Format
        Dynamic Studio Music Module
  .DSN  ODBC Data Source
        SureThing Office Labeler (formerly DesignExpress) Document
        Object System Designer Design
        Orcad Schematic Capture Schematic File
  .DSP  Signature Display Parameters
        Dr. Halo Graphic Screen Driver
        MS Developer Studio Project
  .DSQ  Corel QUERY File
        DASYLab Worksheet Sequence
  .DSR  WordPerfect Driver
        Active Designer File
  .DSRES  MS Dungeon Siege Texture File
  .DSS  Digital Soup Digital Sound File
        DCC Active Designer File
        Digital Speech Standard File (Voice Recorders & IBM's ViaVoice)
  .DSST  ConsumerPoint File (CACR Marketing)
  .DST  PC-RDist Distribution File
        Embroidery Machine Stitch File  (VeePro) [possibly read with Melco Sizer Software]
  .DSW  MS Developer Studio Workspace
        Borland C++ Desktop Settings
  .DSX  Active Designer Binary File
  .DSY  PC Draft Symbol Library
  .DSZ  Embroidery Machine Stitch File  (VeePro)
  .DT_  Macintosh Data File Fork
  .DTA  Data (Various)
        Stata Binary Saved Datasets
        Hidden & Dangerous Archive  [Dragon UnPACKer]
  .DTB  DesignTools PCB Design and Make (printed circuit design - common in UK schools)
  .DTD  SGML Document Definition File
        DesignTools 2D Design (vector drawing - common in UK schools)
  .DTEA  Diagnosis Template Archive
  .DTF  Q&A Database
        MS Exchange Header File (Used when sending to Lotus Notes)
  .DTL  Hal/Supernova/Lunar/LunarPlus Screen Readers/Magnifiers
  .DTM  DigiTrekker Module
        Softshare Delta Translation Map
  .DTP  SecurDesk! Desktop
        Timeworks Publisher Text Document
        Publish-It! Publication
        Pressworks Template File
  .DTQ  Database Tools Query
  .DTS  Digital Surround Audio File Format
        MS Data Transformation Services (Data Transformation Packages used by MS SQL Server)
  .DTX  LaTeX Source and Documentation Archive
        E-Book File
        DocuTech Print6 Engine File (Prints DocuTech Closing Documents)
        LithTech Model Texture File
  .DUN  Dial-Up Network
  .DUP  Duplicate Backup
  .DUS  Readiris Font Dictionary
  .DV   DESQview Script
        Digital Video File
  .DVB  Visual Basic for Applications Macro Project
  .DVC  Lotus File
  .DVF  DV Studio Camcorder Graphics File
  .DVI  TeX Device Independent Document
  .DVP  DESQview Program Information
        AutoCAD Device Parameter
  .DVR  Device Driver
  .DW2  DesignCAD Drawing File
  .DWC  Compressed Archive
  .DWD  DiamondWare Digitized File
  .DWF  Autodesk WHIP! Drawing Web File
        MS WHIP autoCAD REader Drawing Web File
  .DWG  AutoCAD Drawing Database
        Drafix Drawing
  .DWI  Dance With Intensity (dance simulator)
  .DWK  Locked DWG File
  .DWN  Cisco Download File (usually a system update)
        Firmware Update File (several)
        Experimental File Format (.DAWN)
  .DWP  Dweep Game Levels
        DeScribe Document File
  .DWS  Dyadic Workspace File
        AutoCAD Standartization File
  .DWT  AutoCAD Template/Prototype File
        Macromedia Dreamweaver Template File
        Demon's World Game Texture File
  .DWY  Dwyco Video Clip
  .DX   Document Imaging File
        Digital Electric Corporation (DEC) Data Exchange File
        Deus Ex File
  .DXB  Drawing Interchange Binary
  .DXF  AutoCAD Drawing Interchange Format
  .DXL  Dapyx MP3 Explorer (MP3 database organizer)
        DOORS Extension Language
  .DXMAX  Oozic File
  .DXN  Fujitsu dexNet Fax Document
  .DXPACK  DesktopX Object  (customizes the Windows Desktop)
  .DXR  Vegas Jackpot Gold Game File
  .DXTHEME  DesktopX Theme File (customizes the Windows Desktop)
  .DXR  Macromedia Director Protected Movie File
        Dependable Strengths Administrator Resources (Macintosh)
        Green Building Advisor File
  .DYN  Lotus File
  .DZ   Dzip Compressed File