| dbgdt | IAR System Debugger Desktop Data |
| dbgsym | Pidgin IM Debug Symbols Data |
| dbi | Data Explorer Information |
| dblink | Altium Designer Database Link |
| dblog | Debugview++ Debug Log |
| dbml | Database Markup Language File |
| dbo | DarkBASIC Object |
| dbp | Visual Studio Database Project |
| dbproj | Visual Studio 2010 Database Project |
| dcf | ProWorx NXT Database Configuration |
| dci | RAD Studio Delphi Code Insight |
| dcp | Delphi Component Package |
| dcpil | Delphi Compiler Symbolic Information Data |
| dcr | Delphi Component Resource |
| dct | Delphi Component Template |
| dcu | Delphi Compiled Unit |
| dcuil | Delphi .NET Compiled Unit |
| dcurl | Curl Detached Applet |
| dd32 | x64dbg Data |
| dd64 | x64dbg Data |
| dda | GLBasic ASCII Scene Data |
| ddb | ProWorx NXT Descriptor Data with Blocking |
| ddd | Alpha Five Data Dictionary |
| ddf | IAR System C-SPY Device Description Data |
| ddf | ProWorx NXT Descfriptor Data File |
| ddf | Diamond Directive File |
| ddl | Data Definition Language File |
| ddm | Alpha Five Data Dictionary Memo |
| ddp | Delphi Diagram Portfolio |
| dds | Amazon Lumberyard DirectDraw Surface Data |
