• The Asian Development Bank, a non-profit financial institution whose aim is to help developing Asian countries
• The African Development Bank (also AfDB), a non-profit financial institution whose aim is to help developing African countries

or other terms:

• ADB (file format), used by Microsoft Access
• Absolute Debugger, a general purpose debugger for UNIX platforms
• Active Dimension Battle, a battle system in computer gaming
• Adnan Menderes Airport, the IATA airport code for the airport in Izmir, Turkey
• Advanced Digital Broadcast, supplier of digital TV set-top-boxes for cable, satellite, terrestrial and telecommunications
• Agricultural Development Bank, a name shared by several financial institutions, including:
• Agricultural Development Bank of Trinidad and Tobago
• Agricultural Development Bank of Pakistan
• Allgemeine Deutsche Biographie, a biographical reference work in the German language
• Amarillo Design Bureau Inc., the producer of the Star Fleet Universe series of games and related background material.
• Apple Desktop Bus, a bit-serial computer bus for connecting low-speed devices to computers
• Associate of the Drama Board, a former UK drama academic qualification usually from universities.
• Australian Dictionary of Biography, Australia's pre-eminent dictionary of national biography.
• Axis2 Databinding Framework, Axis2's XML to object databinding.