AT or at may refer to:

Geography

Austria

Austria Austria, , bar, Östareich officially the Republic of Austria, is a country in the southern part of Central Europe, lying in the Eastern Alps. It is a federation of nine states, one of which is the capital, Vienna, the most populous ...

(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: * .ac.at (reserved for academic institutions, especially u ...

, Internet country code top-level domain

United States

Atchison County, Kansas Atchison County (county code AT) is a county located in northeastern Kansas, in the Central United States. As of the 2020 census, the county population was 16,348. Its county seat and most populous city is Atchison. The county is named i ...

(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 Tr ...

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

Elsewhere

Anguilla Anguilla ( ) is a British Overseas Territory in the Caribbean. It is one of the most northerly of the Leeward Islands in the Lesser Antilles, lying east of Puerto Rico and the Virgin Islands and directly north of Saint Martin. The territo ...

(World Meteorological Organization country code) * Ashmore and Cartier Islands (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 ( it, Provincia di Asti, Piedmontese: ''Provincia d’Ast'') is a province in the Piedmont region of northern Italy. Its capital is the city of Asti. To the northwest it borders on the Metropolitan City of Turin; to the sou ...

, Italy (ISO 3166-2:IT code)

Science and technology

Computing

* @ (or "

at sign The at sign, , is normally read aloud as "at"; it is also commonly called the at symbol, commercial at, or address sign. It is used as an accounting and invoice abbreviation meaning "at a rate of" (e.g. 7 widgets @ £2 per widget = £14), but ...

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

at (command) In computing, at is a command in Unix-like operating systems, Microsoft Windows, and ReactOS used to schedule commands to be executed once, at a particular time in the future. Design Unix-like On Unix-like operating systems, at reads a series ...

, 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 8028 ...

AT (form factor) In the era of IBM compatible personal computers, the AT form factor comprises the dimensions and layout ( form factor) of the motherboard for the IBM AT. Baby AT motherboards are a little smaller, measuring 8.5" by 13". Like the IBM PC and IBM ...

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

DIN connector The DIN connector is an electrical connector that was standardized by the ' (DIN), the German Institute for Standards, in the early 1970s. The male DIN connectors (plugs) feature a 13.2 mm diameter metal shield with a notch that limits the ...

for a keyboard * The

Hayes command set The Hayes command set (also known as the AT command set) is a specific command language originally developed by Dennis Hayes for the Hayes Smartmodem 300 baud modem in 1981. The command set consists of a series of short text strings which can be ...

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

Biology and medicine

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

transactional analysis Transactional Analysis (TA) is a psychoanalytic theory and method of therapy wherein social interactions (or “transactions”) are analyzed to determine the ego state of the communicator (whether parent-like, childlike, or adult-like) as a b ...

"), a psychological method *

Antithrombin Antithrombin (AT) is a small glycoprotein that inactivates several enzymes of the coagulation system. It is a 432-amino-acid protein produced by the liver. It contains three disulfide bonds and a total of four possible glycosylation sites. α-A ...

, 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, autosomal recessive disease causing severe disability. Ataxia refers to poor coordination and tela ...

, an immunodeficiency disorder * Athletic training

Physics and chemistry

Astatine Astatine is a chemical element with the symbol At and atomic number 85. It is the rarest naturally occurring element in the Earth's crust, occurring only as the decay product of various heavier elements. All of astatine's isotopes are short-li ...

(symbol At), a chemical element * Ampere-turn (symbol At), an International System of Units (MKS) unit of magnetomotive force *

Attotesla The tesla (symbol: T) is the unit of magnetic flux density (also called magnetic B-field strength) in the International System of Units (SI). One tesla is equal to one weber per square metre. The unit was announced during the General Confer ...

, 10⁻¹⁸ tesla, an SI derived unit of magnetic flux density *

Technical atmosphere Technical may refer to: * Technical (vehicle), an improvised fighting vehicle * Technical analysis, a discipline for forecasting the future direction of prices through the study of past market data * Technical drawing, showing how something is co ...

(symbol at), a physical unit of pressure

Other uses in science and technology

* Acceptance testing, in engineering *

Appropriate technology Appropriate technology is a movement (and its manifestations) encompassing technological choice and application that is small-scale, affordable by locals, decentralized, labor-intensive, energy-efficient, environmentally sustainable, and loca ...

, an ideological movement to scale technology to be appropriate to its context * Assistive technology, devices for people with disabilities *

Anti-tank warfare Anti-tank warfare originated from the need to develop technology and tactics to destroy tanks during World War I. Since the Triple Entente deployed the first tanks in 1916, the German Empire developed the first anti-tank weapons. The first devel ...

Automatic transmission An automatic transmission (sometimes abbreviated to auto or AT) is a multi-speed transmission used in internal combustion engine-based motor vehicles that does not require any input from the driver to change forward gears under normal driving ...

, in vehicles

Other uses

* At, a

preposition Prepositions and postpositions, together called adpositions (or broadly, in traditional grammar, simply prepositions), are a class of words used to express spatial or temporal relations (''in'', ''under'', ''towards'', ''before'') or mark various ...

* At (cuneiform), a cuneiform sign * At, 1/100 of a Lao kip, a unit of currency * Aarne–Thompson classification system, used to classify folktales *

Archive Team Archive Team is a group dedicated to digital preservation and web archiving that was co-founded by Jason Scott in 2009. Its primary focus is the copying and preservation of content housed by at-risk online services. Some of its projects include ...

, a digital preservation group * Aliança da Terra, a Brazilian non-governmental organization *

Alternative Tentacles Alternative Tentacles is an independent record label established in 1979 in San Francisco, California. It was used by Dead Kennedys for the self-produced single " California Über Alles". After realizing the potential for an independent label, ...

, an independent record label *

Auckland Transport Auckland Transport (AT) is the council-controlled organisation (CCO) of Auckland Council responsible for transport projects and services. It was established by section 38 of the Local Government (Auckland Council) Act 2009, and operates under ...

, New Zealand, a public transport agency * Autolinee Toscane, Italy, a public transport agency *

Aviation electronics technician (United States Navy) Aviation electronics technician (AT) is a US Navy enlisted rating or job specialty (often called MOS or AFSC by other services). At the paygrade of E-9 ( master chief petty officer), ATs merge with the aviation electrician's mate (AE) rating to ...

, a job specialty *

Royal Air Maroc Royal Air Maroc (; ar, الخطوط الملكية المغربية, , literally ''Royal Moroccan Lines'' or ''Royal Moroccan Airlines''; ber, ⴰⵎⵓⵏⵉ ⴰⵢⵍⴰⵍ ⴰⴳⵍⴷⴰⵏ ⵏ ⴰⵎⵓⵔⴰⴽⵓⵛ, ''Amuni Aylal Age ...

(IATA airline designator AT)