AT or at may refer to:

Geography

Austria

Austria Austria, formally the Republic of Austria, is a landlocked country in Central Europe, lying in the Eastern Alps. It is a federation of nine Federal states of Austria, states, of which the capital Vienna is the List of largest cities in Aust ...

(ISO 2-letter country code) *

.at .at is the Internet country code top-level domain (ccTLD) for Austria. It is administered by nic.at. Second-level domains The .at top-level domain has a number of second-level domains: However, it is also possible to register directly at the to ...

, Internet country code top-level domain

United States

Atchison County, Kansas Atchison County is a county located in the northeastern portion of the U.S. state of Kansas. Its county seat and most populous city is Atchison. As of the 2020 census, the county population was 16,348. The county was named in honor of Dav ...

(county code) * The

Appalachian Trail The Appalachian Trail, also called the A.T., is a hiking trail in the Eastern United States, extending almost between Springer Mountain in Georgia and Mount Katahdin in Maine, and passing through 14 states.Gailey, Chris (2006)"Appalachian Tra ...

(A.T.), a 2,180+ mile long mountainous trail in the Eastern United States

Elsewhere

Antigua and Barbuda Antigua and Barbuda is a Sovereign state, sovereign archipelagic country composed of Antigua, Barbuda, and List of islands of Antigua and Barbuda, numerous other small islands. Antigua and Barbuda has a total area of 440 km2 (170 sq mi), ...

, World Meteorological Organization country code *

Ashmore and Cartier Islands The Territory of Ashmore and Cartier Islands is an uninhabited Australian States and territories of Australia#External territories, external territory consisting of four low-lying tropical islands in two separate reefs (Ashmore and Cartier), ...

(FIPS 10-4 territory code, and obsolete NATO country code) * At, Bihar, village in Aurangabad district of Bihar, India *

Province of Asti The province of Asti (; Piedmontese language, Piedmontese: ''provincia d'Ast'') is a Provinces of Italy, province in the Piedmont region of Italy. Its capital is the city of Asti. To the northwest it borders on the Metropolitan City of Turin; ...

, Italy (ISO 3166-2:IT code) *

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

, LOC MARC code

Politics

Awami Tahreek Awami Tahreek or Qaumi Awami Tehreek, formerly Sindhi Awami Tahreek (), is a Marxist–Leninist–Maoist political party based in the Pakistani province of Sindh, and headquartered in Hyderabad. Formation Awami Tahreek was formed on 5 March 1 ...

a left-wing Pakistani political party

Science and technology

Computing

* @ (or "

at sign The at sign () is an accounting and invoice abbreviation meaning "at a rate of" (e.g. 7 Widget (economics), widgets @ £2 per widget = £14), now seen more widely in email addresses and social media platform User (computing), handles. It is norm ...

"), the punctuation symbol now typically used in e-mail addresses and tweets) *

at (command) at is a shell command for scheduling commands to be executed at a future time; once. The command was developed for Unix and is available on Unix and Unix-like systems, Windows, and ReactOS. Variants Unix-like On Unix-like operating systems, ...

, used to schedule tasks or other commands to be performed or run at a certain time *

IBM Personal Computer/AT The IBM Personal Computer AT (model 5170, abbreviated as IBM AT or PC/AT) was released in 1984 as the fourth model in the IBM Personal Computer line, following the IBM PC/XT and its IBM Portable PC variant. It was designed around the Intel 8 ...

AT (form factor) In the era of IBM compatible personal computers, the AT form factor comprises the dimensions and layout (Comparison of computer form factors, form factor) of the motherboard for the IBM AT. Baby AT motherboards are slightly smaller, measuring 8. ...

for motherboards and computer cases ** AT connector, a five-pin

DIN connector The DIN connector is an electrical signal connector that was standardized by the (DIN), the German Institute for Standards, in the mid 1950s, initially with three pins for mono, but when stereo connections and gear appeared in the late 1950s, v ...

for a keyboard *

AT Protocol The AT Protocol (Authenticated Transfer Protocol, pronounced " @ protocol" and commonly shortened to ATProto) is a protocol and open standard for distributed social networking services. It is under development by Bluesky Social PBC, a public ...

, a decentralized social networking protocol by

Bluesky Bluesky is a microblogging social media social networking service, service. Users can share short posts containing text, images, and videos. It is owned by Bluesky Social PBC, a benefit corporation based in the United States. Bluesky was dev ...

* The

Hayes command set The Hayes command set (also known as the AT command set) is a specific command language originally developed by Dale Heatherington and Dennis Hayes for the Hayes Smartmodem in 1981. The command set consists of a series of short text string ...

for computer modems (each command begins with the character string "AT")

Biology and medicine

Anaerobic threshold Lactate inflection point (LIP) is the exercise intensity at which the blood concentration of lactate and/or lactic acid begins to increase rapidly. It is often expressed as 85% of maximum heart rate or 75% of maximum oxygen intake. When exercisin ...

, in physiology * ''Análisis transaccional'' (Spanish for "

transactional analysis Transactional analysis is a psychoanalytic theory and method of therapy wherein social interactions (or "transactions") are analyzed to determine the id, ego, and superego, ego state of the communicator (whether parent-like, childlike, or adult- ...

"), a psychological method *

Antithrombin Antithrombin (AT) is a small glycoprotein that inactivates several enzymes of the coagulation system. It is a 464-amino-acid protein produced by the liver. It contains three disulfide bonds and a total of four possible glycosylation sites. α-An ...

, a small protein molecule *

Ataxia–telangiectasia Ataxia–telangiectasia (AT or A–T), also referred to as ataxia–telangiectasia syndrome or Louis–Bar syndrome, is a rare, neurodegenerative disease causing severe disability. Ataxia refers to poor coordination and telangiectasia to small dil ...

, an immunodeficiency disorder * Athletic training * Atrial tachycardia

Physics and chemistry

* Astatine (symbol At), a chemical element * Ampere-turn (symbol A t), an International System of Units (MKS) unit of magnetomotive force * Attotesla (symbol aT), 10⁻¹⁸ tesla, an SI derived unit of magnetic flux density * Technical atmosphere (symbol at), a physical unit of pressure

Other uses in science and technology

* Acceptance testing, in engineering * Appropriate technology, an ideological movement to scale technology to be appropriate to its context * Assistive technology, devices for people with disabilities * Anti-tank warfare * Automatic transmission, in vehicles

Other uses

* At, a preposition * At (cuneiform), a cuneiform sign * At, 1/100 of a Lao kip, a unit of currency * AT (), a Ukrainian form of company, equivalent to joint-stock company#Ukraine, joint-stock company * Aarne–Thompson classification system, used to classify folktales * Archive Team, a digital preservation group * Aliança da Terra, a Brazilian non-governmental organization * Alternative Tentacles, an independent record label * Auckland Transport, New Zealand, a public transport agency * Audiotool, a Digital audio workstation * Autolinee Toscane, Italy, a public transport agency * Aviation electronics technician (United States Navy), a job specialty * Royal Air Maroc (IATA airline designator AT) * A US Navy hull classification symbol: List of auxiliaries of the United States Navy#Fleet tugs (AT), Fleet tug (AT)