| ddf | Alpha Journal Pro Document |
| ddf | My Personal Diary Document |
| ddif | DIGITAL Document Interchange Format |
| ddrw | ClarisDraw Drawing |
| de | DrawExpress Diagram Document |
| dec | DEC DX Document |
| ded | Dr. Engrave Document |
| des | Intuit QuickBooks Template |
| des | OpenVSP v2 VSP Design Document |
| desd | VivaDesigner Template |
| design | Microsoft Expression Design Drawing |
| dfb | Data Flask Formula |
| dfd | Silverrun DFD Document |
| dff | RenderWare 3D Model |
| dfg | Data Flask Grid |
| dfm | Help and Manual eBook Template |
| dft | Solid Edge Draft Document |
| dfti | FlexiWrite Document |
| dfx | Softdesk Drafix CAD Document |
| dg | Auto-trol Tech Illustrator Drawing |
| dg3 | DeltaGraph Document |
| dgk | Delcam 3D Model |
| dgm | Autodesk AutoCAD Civil 3D DGM Document |
| dgm | Lotus Freelance Graphics Diagram |
| dgn | Bentley MicroStation Drawing |
| dgpd | DeltaGraph Document |
| dgrh | DeltaGraph for Mac Document |
| dgs | Dagesh Pro Document |
| dhw | ACECAD DigiMemo Memo Document |
| dia | Dia Diagram |
| dif | Data Interchange Format |
| diz | Archive Description |
| djc | RootPro CAD Document |
| dma | IBM Rational DOORS Template |
| dmf | Delgine DeleD Model File |