ACT is a three-letter abbreviation with multiple meanings:

• Acceptance and Commitment Therapy, a therapy based on a pragmatic philosophy called functional contextualism.
• ACT (cognitive model), a symbolic cognitive architecture, created by John R. Anderson.
• ACT!, contact management software.
• ACT (examination), a college entrance exam, competitor to the SAT.
• ACT New Zealand, a political party and movement in New Zealand.
• ACT Theatre, in Seattle, Washington.
• Act of Parliament, a law enacted by the parliament.
• Ada Core Technologies, a computer software company that develops an Ada compiler, tools and libraries.
• Allied Command Transformation, the NATO strategic command.
• America Coming Together, a United States political group.
• American Conservatory Theater, a repertory theater and theater school in San Francisco.
• Annual Change Traffic, the fraction of a software product's source code that changes in a year.
• Applied Computer Techniques, a computer services company founded in 1965. In 1985 it was renamed Apricot Computers.
• Artemisinin-based Combination Therapy, a treatment for malaria.
• Ascot railway station, a railway station in the United Kingdom with the National Rail code "ACT".
• Association for Citizenship Teaching, a professional subject association for teachers of citizenship.
• Association for Competitive Technology, a pro-Microsoft lobby group.
• Atacama Cosmology Telescope, a telescope under construction in the Andes in Chile.
• Australian Capital Territory, the capital territory of the Commonwealth of Australia.
• Aviation Composite Technology, an aircraft manufacturer in the Philippines.
• Waco Regional Airport, an airport in Waco, Texas, United States, which has the IATA airport code "ACT".

See also

• Act (disambiguation)

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