ADT

ADT is a three-letter acronym that may refer to:
*Abstract data type, a computer programming term
*Algebraic data type, a term from functional programming
*Asynchronous data transfer, a method of transferring data
*Automatic double tracking, an audio recording technology invented for The Beatles
*American Discovery Trail, a coast-to-coast hiking trail across the mid-tier of the United States.
*Average Daily Traffic, to show the volume of traffic on a road in transportation planning
*Average downtime, a simple quantification of a system's reliability
*Apple Disk Transfer, software for exchanging floppy disk images between Apple II computers and host computers over serial links
*ADT Security Services, a division of Tyco International, formerly American District Telegraph
*ADT College, a City Technology College in London
*Autodesk Architectural Desktop, CAD software from Autodesk
*"Admission, Discharge, and Transfer", a message type used in Health Level 7 formatted communication
*Adult diphtheria and tetanus vaccination
*Atlantic Daylight Time
*Active Denial Technology