| dmt | Delphi Menu Template |
| dmx | Microsoft SQL Server Data Mining Extension |
| dnx | IBM Rational Software Architect DNX Diagram |
| do | Stata Batch File |
| dob | Visual Basic ActiveX Document Form |
| docbook | DocBook Document |
| docset | Doxygen Document Set File |
| dof | Delphi Option File |
| doh | Geoworks GEOS Dependency Information |
| dox | Visual Basic ActiveX Document Binary Form |
| doxy | Doxygen Data |
| dpb | ProWorx NXT Descriptor Pointer with Blocking |
| dpd | ABC Dyadic Predicate Data |
| dpf | ProWorx NXT Descfriptor Pointer File |
| dpk | Delphi Package |
| dpkw | Delphi Package for Windows |
| dpl | Delphi Package Library |
| dplt | AppleScript Droplet |
| drc | Delphi Resource Strings |
| dres | Delphi Compiled Resource |
| dro | Delphi Repository Object |
| ds | DAZ Studio ASCII Script |
| dsa | DAZ Studio ASCII Script |
| dsb | DAZ Studio Binary Script |
| dse | DAZ Studio Script Encrypted |
| dsf | ProWorx NXT Data Setup File |
| dsl | Domain-Specific Language File |
| dso | SymbianOS Dynamic Shared Object |
| dsr | Visual Basic Designer File |
| dsu | ProWorx NXT Data Setup File |
| dsw | Microsoft Developer Studio Workspace |
| dsx | Visual Basic Designer Binary File |
| dsym | Xcode Debugging Symbols |
| dta | Stata Data File |
| dtb | Linux Device Tree Blob |
