DD

DD, dd, or other variants may refer to:

Computing

• dd (Unix), a program that copies and convert files and data
• .dd, a hypothetical domain name for the German Democratic Republic
• Deckadance, a DJ program for Windows and Mac OS X designed by Image-Line
• Deployment descriptor, a component in Java Platform, Enterprise Edition applications
• Dolby Digital, the name for audio compression technologies developed by Dolby Laboratories
• Double density, a capacity designation on magnetic storage, usually floppy disks
• dd, an HTML element for specifying definition data

Military

• DD tank, an amphibious tank
• Dishonorable discharge, a punitive discharge in the US Military
• DD, the US Navy hull classification for destroyers

Companies

• Dunkin' Donuts, a coffee and baked goods franchise
• DuPont's stock ticker symbol
• Nok Air's IATA code

Other uses

• Dd (digraph), a digraph in the Welsh language
• D-D locomotive, the UIC classification for a railway locomotive with two four-axle bogies
• DD National or DD1, an Indian national channel
• Daredevil (Marvel Comics)
• Data Deficient, a rating on the IUCN Red List of Threatened Species
• Decimal degrees, geographic coordinates shown using decimal fractions
• Designated driver, an individual within a group of people drinking alcoholic beverages who remains sober to drive others home
• Doctor of Divinity or D.D.
• DD, the licence plate code for Dresden, Germany
• DD, a brassiere measurement