| dl | FLEXnet Manager Debug Log |
| dl4 | Lindab DIMsilencer Data |
| dla | Defense Department DLA Procurement Data |
| dlc | JDownloader Download Link Container |
| dlf | EES Dynamically Linked Function |
| dlis | Digital Log Interchange Standard File |
| dlog | EasySYNC EasyLogger Data Log |
| dlog | Avid Pro Tools Log |
| dlpext | DESlock+ Data |
| dlpf | DinkeyLook Diagnostic Information Data |
| dlt | DELTA Binary Dataset File |
| dltemp | UC Browser Incomplete Download |
| dlv | Catia V4 Export Data |
| dlv3 | Catia V3 Export Data |
| dlv4 | Catia V4 Export Data |
| dlx | DIALux Project |
| dly | Xilinx ISE ReportGen Delay Information |
| dly | GHCN Daily Data |
| dlz | CPT Crosswords Data |
| dl_ | Compressed DLL File |
| dmat | libigl Dense Matrices |
| dmb | Sybase PowerDesigner Data Movement Model Backup |
| dmbk | Document Manager Backup Data |
| dme | Neoss Library Data |
| dmit | Algor Simulation Direct Memory Image Transfer Data |
| dmm | Sybase PowerDesigner Data Movement Model |
| dmms | DropMind Map Style |
| dmmx | DropMind XML Map Bundle |
| dmn | SAS Stat Studio Metadata |
| dmnd | DIAMOND Data |
| dmnd | SonicSelector Data |
| dmo | TI Derive Demo |
| dmp | DB/TextWorks Exported Records File |
| dmp | Windows Memory Dump |
| dmpx | Oracle Database Application Dump |