| DMD | Corel Data Modeling Desktop |
| DMD | Visual dBASE Data Module |
| DMF | Delusion/XTracker Digital Music File |
| DMF | Packed Amiga Disk Image |
| DMO | Duke Nukem, Redneck Rampage Saved Game |
| DMP | Dump (various) |
| DMS | Packrat Database Index |
| DMS | Compressed Archive |
| DNE | Darn v5+ (Windows) Events List |
| DNE | Netica Bayes Net Text File (More info) |
| DOB | User Document Form File |
| DOC | Document or Documentation (various) |
| DOC | MS Word Document |
| DOG | Laughing Dog Screen Saver |
| DOH | Geoworks Dependency Information File |
| DOS | Text File/DOS Specification Info |
| DOT | Microsoft Word Document Template |
| DOT | Corel Draw Line Description |
| DOX | MultiMate Word Processor Document |
| DOX | Microsoft ActiveX Binary Form |
| DOX | Text File |
| DOZ | VENDINFO Description Out of Zip File |
| DP | DataPhile Data File |
| DP | Daily Planner Calendar File |
| DPA | Serif DrawPlus Animation |
| DPG | Windows Applications Manager Deleted Program Group |
| DPI | Pointline Image |
| DPJ | DeskProto CAM Project File |
| DPK | Delphi Package File |
| DPL | Borland Delphi 3 Packed Library |
| DPP | Serif DrawPlus Drawing |
| DPR | Borland C++ (or Delphi) Default Project |
| DPT | Publish-It! Publication File |
| DPX | Digital Moving Picture Exchange |
| DQY | MS Excel ODBC Query File |
| DRC | Orcad Schematic Capture Design Rules Check Report File |
| DRN | Darn for DOS |
| DRS | Corel Draw Perfect Font |
| DRS | WordPerfect Driver Resource |
| DRS | Age of Empires 2 Archive |
| DRV | Device Driver |
| DRW | Micrografx Vector Graphic |
| DRW | Drawing (various) |
| DRX | Adobe Photoshop Tutorial |
| DS | TWAIN Data source file |
| DS4 | Micrografx Designer Graphics (ver 4) |
| DSC | Oracle Discard File |
| DSC | Nikon Coolpix Disk Identification File |
| DSD | DataShaper Database File |
| DSD | Document Structure Definition File |
| DSF | Micrografx Designer v7.x |
| DSF | Delusion/XTracker Digital Sample |
| DSG | Doom Saved Game |
| DSK | Archive for Lotus Smart Suite Setup |
| DSK | Borland C++ or Turbo Pascal Project Desktop File |
| DSK | Novell Driver File |
| DSL | Lingvo User Feature Dictionary |
| DSM | Dynamic Studio Music Module |
| DSM | Delphi Symbol File |
| DSM | Digital Sound Module Tracker Format |
| DSN | ODBC Data Source |
| DSN | SureThing Office Labeler Document |
| DSN | Orcad Schematic Capture Schematic File |
| DSP | Microsoft Developer Studio Project |
| DSP | Dr. Halo Graphic Screen Driver |
| DSP | Signature Display Parameters |
| DSQ | Corel QUERY File |
| DSR | Active Designer File |
| DSR | WordPerfect Driver |
| DSS | Digital Soup Digital Sound File |
| DSS | Digital Speech Standard File |
| DST | Micrografx Designer Template |
| DST | Embroidery Machines Graphics File |
| DSW | Microsoft Developer Studio Workspace |
| DSW | Borland C++ Desktop Settings |
| DSX | Active Designer Binary File |
| DT_ | Macintosh Data File Fork |
| DTA | Data (various) |
| DTD | SGML Document Type Definition File |
| DTF | Symantec Q&A Relational Database Data File |
| DTM | DigiTrakker Module |
| DTP | Pressworks Template File |
| DTP | Timeworks Publisher Text Document |
| DTP | SecurDesk! Desktop |
| DTP | Datastorm Technologies, Inc. ProComm Program Patch |
| DUN | Dial-Up Network |
| DUP | Duplicate Backup |
| DV | Digital Video File |
| DV | DESQview Script |
| DVB | Visual Basic for Applications Macro Project |
| DVC | Lotus File |
| DVF | DV Studio Camcorder Graphics File |
| DVI | TeX Device Independent Document |
| DVM | Movie File |
| DVP | DESQview Program Information |
| DVP | AutoCAD Device Parameter |
| DVR | Device Driver |
| DW2 | DesignCAD Drawing File |
| DWC | Compressed Archive |
| DWD | DiamondWare Digitized File |
| DWF | Autodesk Vector Graphic |
| DWG | AutoCAD Drawing Database |
| DWG | Drafix CAD Drawing |
| DWP | Dweep Game Levels |
| DWP | DeScribe Document File |
| DWS | Dyadic Workspace File |
| DWS | AutoCAD Standardisation File |
| DWT | AutoCAD Template/Prototype File |
| DWT | Dreamweaver Template File |
| DX | MultiMate Word Processor Document |
| DX | Digital Electric Corporation (DEC) Data Exchange File |
| DX | Document Imaging File |
| DX | Autotrol Document Image |
| DXB | AutoCAD Database |
| DXB | Drawing Interchange Binary |
| DXF | AutoCAD Drawing Interchange File Format |
| DXF | Data Exchange File |
| DXN | Fujitsu dexNET Fax Document |
| DXR | Macromedia Director Protected Movie File |
| DYN | Lotus File |