UDF

UDF stands for:

Aviation

• UHF Direction Finder, a kind of radio direction finding (RDF)
• Unducted fan, a type of jet engine
• User Development Fee - Airport Tax

Computer Science

• Uniqueness Database Files, a Windows XP Professional configuration text file
• Universal Disk Format, an operating-system-independent file system commonly used on DVD and other digital media
• User Defined Field, a user-defined field that can be added to tables in a database
• User-defined function, is a function provided by the user of a program or environment
• User-defined format, is a file format type used in transferring data from one system to another

Politics

• Ulster Defence Force, a loyalist paramilitary in Northern Ireland
• Union of Democratic Forces, the name of several political parties
• Union for French Democracy or Union pour la Démocratie Française, a centrist French political party
• Union of Democratic Forces (СДС), a political party in Bulgaria
• United Democratic Forces (ОДС), an electoral alliance in Bulgaria
• United Democratic Forces of Belarus, a coalition of political parties participating as the main opposition group during the 2006 presidential election
• United Democratic Front, the name of several political parties
• United Democratic Front (South Africa), a former anti-Apartheid movement in South Africa

Military

• Union Defence Force, the official name of the military forces of a few countries.
  • Union Defence Force (South Africa), the predecessor of the South African Defence Force from 1912 to 1957
  • Union Defence Force (UAE), the armed forces of the United Arab Emirates

Other

• Ultra Deep Field, a view of the distant universe taken in 2004 by the Hubble space telescope
• United Dairy Farmers, an American chain of ice cream shops
• Up Side Down Suspension Forks, used in Motorcycles and Mountain bikes
• Uncharted: Drake's Fortune, a 2007 PlayStation 3 action-adventure video game developed by Naughty Dog