| Extension | Description | File Type |
|---|
| d | D Source Code File | Developer Files |
| d10 | Drake Software Data File | Data Files |
| d10 | H&R Block Deduction Pro File | Misc Files |
| d2s | Diablo II Saved Game File | Game Files |
| daa | PowerISO Direct Access Archive | Disk Image Files |
| dap | Download Accelerator Plus Download File | Misc Files |
| dat | Inno Setup Uninstall Log | Data Files |
| dat | DAT | Data Files |
| dat | VCD Audio/Video Data | Video Files |
| data | CoreFSIF database | Data Files |
| dav | DVR365 CCTV Video File | Video Files |
| db | Database File | Data Files |
| db3 | dBase III Database File | Data Files |
| dbc | Visual FoxPro Databse File | Data Files |
| dbd | DemoShield Project File | Multimedia Files |
| dbf | Database File | Data Files |
| dbk | Sony Ericsson Phone Backup File | Backup Files |
| dbx | Outlook Express E-mail Folder | Misc Files |
| dcf | DRM Content Format Delivery File | Audio Files |
| dcm | DICOM Image File | Graphic Files |
| dcr | Shockwave File | Web Files |
| dct | Arcview Dictionary File | Geographical Files |
| dct | AutoCAD Dictionary File | CAD Files |
| dctmp | DC++ partially downloaded file | Misc Files |
| ddat | DivX Temporary File | Video Files |
| ddm | Alpha Five Table Objects File | Data Files |
| ddp | Delphi Diagram Portfolio | Developer Files |
| dds | Direct Draw Surface File | Graphic Files |
| ddt | Football Manager Data File | Game Files |
| ddt | Jill of the Jungle File | Game Files |
| de | MetaProducts Download Express Partial Download File | Misc Files |
| deb | Debian Software Package | Archived Files |
| dec | Unix Hyperhelp Support Files | Misc Files |
| def | Module Definition File | Developer Files |
| dem | Arcview Digital Elevation Model File | Geographical Files |
| dem | Half-Life Demo File | 3D Files |
| deploy | DeployMaster Deploy File | Developer Files |
| des | Quickbooks Form Template File | Misc Files |
| deskthemepack | Windows 8 Theme Pack Files | System Files |
| desktop | Desktop X Theme File | Graphic Files |
| dex | Dalvik File | Executable Files |
| dex | Excel File | Spreadsheet Files |
| dff | RenderWare File | 3D Files |
| dgdat | DoubleGIS Database File | Data Files |
| dgn | ArcView Design Drawing File | Geographical Files |
| dhy | Adobe Bridge File | Multimedia Files |
| dic | Dictionary File | Text Files |
| dinfo | DivX Temporary Video Information File | Settings Files |
| dir | Adobe Director Movie File | Video Files |
| disabled | Spybot Search & Destroy Disabled File | Misc Files |
| diskdefines | Live CD Information File | System Files |
| divx | DivX Encoded Movie File | Video Files |
| diz | Zip Archive Description File | Text Files |
| djv | DJVu Scanned File | Graphic Files |
| djvu | DjVu File | Archived Files |
| dl | Zoo Tycoon 2 Game Data File | Game Files |
| dlc | JDownloader download link container | Encoded Files |
| dll | Dynamic Link Library | System Files |
| dlm | 3ds Max File | 3D Files |
| dlm | Adobe Download Manager Partial File | Misc Files |
| dlm | File Transfer Manager Partial File | Misc Files |
| dl_ | DLL Backup FIle | System Files |
| dm | Call Of Duty Demo File | Game Files |
| dmf | D-Lusion Music Files | Audio Files |
| DMFr | Download Master Temporary File | Web Files |
| dmg | Macintosh Disk Image | Disk Image Files |
| dmp | Memory Dump File | System Files |
| dmsk | DivX Web Player Temporary File | Video Files |
| dng | Adobe Digital Negative File | Graphic Files |
| dnl | DNL eBook File | Misc Files |
| do | Java Servlet File | Web Files |
| doc | Word Document | Document Files |
| docm | Word 2007/2010 Open XML Macro-enabled Document File | Text Files |
| docx | Microsoft Word Open XML Document | Text Files |
| dol | Nintendo Executable File | Executable Files |
| dot | Word Document Template File | Layout Files |
| dotx | Microsoft Word 2007 template File | Audio Files |
| download | Download File | Misc Files |
| downloading | Partially Downloaded File | Misc Files |
| dpg | Nintendo DS MPEG Video File | 3D Files |
| dps | DivX Player Skin File | Settings Files |
| dream | Microsoft DreamScene File | System Files |
| dropbox | Dropbox File | Data Files |
| drv | Device Driver File | System Files |
| drw | Drawing File Format | Graphic Files |
| ds | Twain Data Source File | Misc Files |
| dsc | Disk Identification File | Misc Files |
| dsim | Digital Simulator FIle | Misc Files |
| dsk | Generic Disk Image File | Disk Image Files |
| dsn | ODBC Data Source File | Data Files |
| dst | Embroidary Stich File | Misc Files |
| dsv | DeSmuME Saved Game File | Game Files |
| ds_store | Mac Os X Folder Information File | Settings Files |
| dt | PowerBasic File | Developer Files |
| dt2 | Windows Live Messenger Emoticon File | Graphic Files |
| dta | Stata Dataset File | Data Files |
| dtapart | DownloadThemAll Partially Downloaded File | Misc Files |
| dtd | Document Type Definition | Text Files |
| dtm | Digital Terrain Model File | Geographical Files |
| dts | DTS Audio File | Audio Files |
| dump | Library Symbols File | Developer Files |
| dvd | Layer Break Information File | Disk Image Files |
| dvd | MS DOS Device Driver | System Files |
| dvdrip | DVD Ripped File | Video Files |
| dvr | Media Center Recorded File | Video Files |
| dwf | Design Web Format File | 3D Files |
| dwg | AutoCAD Drawing Database File | CAD Files |
| dwl | Drawing Lock Files | CAD Files |
| dxf | Drawing Exchange Format File | CAD Files |
| dxr | Adobe Director Movie File | Video Files |
| dxtorylic | Dxtory Licence File | Misc Files |