| d | GCC Dependency File |
| d4 | Dataphor Source Code |
| d43 | IAR System MSP430 Debug Data |
| d4c | Dataphor Catalog Data |
| da | Gcov Compiled Output |
| da | Gcov Data File |
| dabriefcase | RemObjects Data Abstract File Briefcase |
| daconfig | RemObjects Data Abstract Configuration |
| daconnections | RemObjects Data Abstract Connections Data |
| dacpac | Microsoft SQL Server Data Tier Application Package |
| dad | RemObjects Delphi Data Abstract Driver |
| dadiagrams | RemObjects Data Abstract Data Diagrams |
| dadx | Eclipse Document Access Definition Extension |
| dart | Dart Source Code |
| das | Atari Jaguar DSP Assembly Source |
| daschema | RemObjects Data Abstract Schema |
| datasource | Microsoft Visual Studio Data Source |
| db | Atari Jaguar Debugger Script |
| db2sp | Visual Studio DB2 Create Procedure Statement Data |
| db2tbl | Microsoft Visual Studio DB2 Table Script |
| db2tr | Microsoft Visual Studio DB2 Trigger Script |
| db2udf | Visual Studio DB2 User Defined Function Data |
| db2vw | Microsoft Visual Studio DB2 View Script |
| dba | Amazon Lumberyard Animation Database |
| dba | DarkBASIC Source Code |
| dbag | WinSQL DataBag Data |
| dbd | Modula-2 Debug Data |
| dbf | Alpha Five Table Data |
| dbf | Microsoft Visual FoxPro Database Table |
| dbg | IAR System XLink Debug Data |
