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Airport

An airport is an aerodrome with extended facilities, mostly for commercial air transport. Airports usually consist of a landing area, which comprises an aerially accessible open space including at least one operationally active surface such as a runway for a plane to take off and to land or a helipad, and often includes adjacent utility buildings such as control towers, hangars and terminals, to maintain and monitor aircraft. Larger airports may have airport aprons, taxiway bridges, air traffic control centres, passenger facilities such as restaurants and lounges, and emergency services. In some countries, the US in particular, airports also typically have one or more fixed-base operators, serving general aviation.

Airport operations are extremely complex, with a complicated system of aircraft support services, passenger services, and aircraft control services contained within the operation. Thus airports can be major employers, as well as important hubs for tourism and other kinds of transit. Because they are sites of operation for heavy machinery, a number of regulations and safety measures have been implemented in airports, in order to reduce hazards. Additionally, airports have major local environmental impacts, as both large sources of air pollution, noise pollution and other environmental impacts, making them sites that acutely experience the environmental effects of aviation. Airports are also vulnerable infrastructure to extreme weather, climate change caused sea level rise and other disasters.

Terminology
The terms aerodrome, airfield, and airstrip also refer to airports, and the terms heliport, seaplane base, and STOLport refer to airports dedicated exclusively to helicopters, seaplanes, and short take-off and landing aircraft.

In colloquial use in certain environments, the terms airport and aerodrome are often interchanged. However, in general, the term airport may imply or confer a certain stature upon the aviation facility that other aerodromes may not have achieved. In some jurisdictions, airport is a legal term of art reserved exclusively for those aerodromes certified or licensed as airports by the relevant civil aviation authority after meeting specified certification criteria or regulatory requirements.

That is to say, all airports are aerodromes, but not all aerodromes are airports. In jurisdictions where there is no legal distinction between aerodrome and airport, which term to use in the name of an aerodrome may be a commercial decision. In US technical/legal usage, landing area is used instead of aerodrome, and airport means "a landing area used regularly by aircraft for receiving or discharging passengers or cargo".

Types of airports
An airport solely serving helicopters is called a heliport. An airport for use by seaplanes and amphibious aircraft is called a seaplane base. Such a base typically includes a stretch of open water for takeoffs and landings, and seaplane docks for tying-up.

An international airport has additional facilities for customs and passport control as well as incorporating all the aforementioned elements. Such airports rank among the most complex and largest of all built typologies, with 15 of the top 50 buildings by floor area being airport terminals.

Management
Smaller or less-developed airfields, which represent the vast majority, often have a single runway shorter than 1000 m. Larger airports for airline flights generally have paved runways of 2000 m or longer. Skyline Airport in Inkom, Idaho, has a runway that is only 122 m long.

In the United States, the minimum dimensions for dry, hard landing fields are defined by the FAR Landing And Takeoff Field Lengths. These include considerations for safety margins during landing and takeoff.

The longest public-use runway in the world is at Qamdo Bamda Airport in China. It has a length of 5500 m. The world's widest paved runway is at Ulyanovsk Vostochny Airport in Russia and is 105 m wide.

, the CIA stated that there were approximately 44,000 "airports or airfields recognizable from the air" around the world, including 15,095 in the US, the US having the most in the world.

Airport ownership and operation

Most of the world's large airports are owned by local, regional, or national government bodies who then lease the airport to private corporations who oversee the airport's operation. For example, in the UK the state-owned British Airports Authority originally operated eight of the nation's major commercial airports – it was subsequently privatized in the late 1980s, and following its takeover by the Spanish Ferrovial consortium in 2006, has been further divested and downsized to operating just Heathrow. Germany's Frankfurt Airport is managed by the quasi-private firm Fraport. While in India GMR Group operates, through joint ventures, Indira Gandhi International Airport and Rajiv Gandhi International Airport. Bengaluru International Airport is controlled by Fairfax .Chhatrapati Shivaji International Airport, Chaudhary Charan Singh International Airport, Mangalore International Airport, Thiruvananthapuram International Airport, Lokpriya Gopinath Bordoloi International Airport, Jaipur International Airport, Sardar Vallabhbhai Patel International Airport are operated by Adani Group through a Public Private Partnership wherein Adani Group, the operator pays Airports Authority of India, the owner of the airports, a predetermined sum of money based on the number of passengers handled by the airports. The rest of India's airports are managed by the Airports Authority of India. In Pakistan nearly all civilian airports are owned and operated by the Pakistan Civil Aviation Authority except for Sialkot International Airport which has the distinction of being the first privately owned public airport in Pakistan and South Asia.

In the US, commercial airports are generally operated directly by government entities or government-created airport authorities (also known as port authorities), such as the Los Angeles World Airports authority that oversees several airports in the Greater Los Angeles area, including Los Angeles International Airport.

In Canada, the federal authority, Transport Canada, divested itself of all but the remotest airports in 1999/2000. Now most airports in Canada are operated by individual legal authorities, such as Vancouver International Airport Authority (although still owned by Transport Canada); some airports, such as Boundary Bay Airport and Pitt Meadows Airport, are municipally owned.

Many US airports still lease part or all of their facilities to outside firms, who operate functions such as retail management and parking. All US commercial airport runways are certified by the FAA under the Code of Federal Regulations Title 14 Part 139, "Certification of Commercial Service Airports" but maintained by the local airport under the regulatory authority of the FAA.

Despite the reluctance to privatize airports in the US (contrary to the FAA sponsoring a privatization program since 1996), the government-owned, contractor-operated (GOCO) arrangement is the standard for the operation of commercial airports in the rest of the world.

Airport funding
The Airport & Airway Trust Fund (AATF) was created by the Airport and Airway Development in 1970 which finances aviation programs in the United States. Airport Improvement Program (AIP), Facilities and Equipment (F&E), and Research, Engineering, and Development (RE&D) are the three major accounts of Federal Aviation Administration which are financed by the AATF, as well as pays for the FAA's Operation and Maintenance (O&M) account. The funding of these accounts are dependent on the taxes the airports generate of revenues. Passenger tickets, fuel, and cargo tax are the taxes that are paid by the passengers and airlines help fund these accounts.

Airport revenue
Airports revenues are divided into three major parts: aeronautical revenue, non-aeronautical revenue, and non-operating revenue. Aeronautical revenue makes up 50% in 2021 (from 54% and 48% in 2019 and 2020, non-aeronautical revenue makes up 34% (40%, 39% in previous years), and non-operating revenue makes up 16% (6%, 14%) of the total revenue of airports.

Aeronautical revenue
Aeronautical revenue are generated through airline rents and landing, passenger service, parking, and hangar fees. Landing fees are charged per aircraft for landing an airplane in the airport property. Landing fees are calculated through the landing weight and the size of the aircraft which varies but most of the airports have a fixed rate and a charge extra for extra weight. Passenger service fees are charges per passengers for the facilities used on a flight like water, food, wifi and shows which is paid while paying for an airline ticket. Aircraft parking is also a major revenue source for airports. Aircraft are parked for a certain amount of time before or after takeoff and have to pay to park there. Every airport has its own rates of parking, for example, John F Kennedy airport in New York City charges $45 per hour for a plane of 100,000 pounds and the price increases with weight.

Non-aeronautical revenue
Non-aeronautical revenue is gained through things other than aircraft operations. It includes lease revenue from compatible land-use development, non-aeronautical building leases, retail and concession sales, rental car operations, parking and in-airport advertising. Concession revenue is one big part of non-aeronautical revenue airports makes through duty free, bookstores, restaurants and money exchange. Car parking is a growing source of revenue for airports, as more people use the parking facilities of the airport. O'Hare International Airport in Chicago charges $2 per hour for every car.

Price regulation
Many airports are local monopolies. To prevent them from abusing their market power, governments regulate how much airports may charge to airlines, using price-cap regulation.

Landside and airside areas
Airports are divided into landside and airside zones. The landside is subject to fewer special laws and is part of the public realm, while access to the airside zone is tightly controlled. Landside facilities may include publicly accessible airport check-in desks, shops and ground transportation facilities. The airside area includes all parts of the airport around the aircraft, and the parts of the buildings that are restricted to staff, and sections of these extended to travelling, airside shopping, dining, or waiting passengers. Depending on the airport, passengers and staff must be checked by security or border control before being permitted to enter the airside zone. Conversely, passengers arriving from an international flight must pass through border control and customs to access the landside area, in which they exit, unless in airside transit. Most multi-terminal airports have (variously termed) flight/passenger/air connections buses, moving walkways and/or people movers for inter-terminal airside transit. Their airlines can arrange for baggage to be routed directly to the passenger's destination. Most major airports issue a secure keycard, an airside pass to employees, to assist in their reliable, standardized and efficient verification of identity.

Facilities

A terminal is a building with passenger facilities. Small airports have one terminal. Large ones often have multiple terminals, though some large airports, like Amsterdam Airport Schiphol, still have one terminal. The terminal has a series of gates, which provide passengers with access to the plane.

The following facilities are essential for departing passengers:
 * Check-in facilities, including a baggage drop-off
 * Security checks
 * Passport control (for some international flights)
 * Gates
 * Waiting areas

The following facilities are essential for arriving passengers:
 * Passport control (international arrivals only)
 * Baggage reclaim facilities, often in the form of a carousel
 * Customs (international arrivals only)
 * A landside meeting place

For both sets of passengers, there must be a link between the passenger facilities and the aircraft, such as jet bridges or airstairs. There also needs to be a baggage handling system, to transport baggage from the baggage drop-off to departing planes, and from arriving planes to the baggage reclaim.

The area where the aircraft parks to load passengers and baggage is known as an apron or ramp (or incorrectly, "the tarmac").

Airports with international flights have customs and immigration facilities. However, as some countries have agreements that allow travel between them without customs and immigrations, such facilities are not a definitive need for an international airport. International flights often require a higher level of physical security, although in recent years, many countries have adopted the same level of security for international and domestic travel.

"Floating airports" are being designed which could be located out at sea and which would use designs such as pneumatic stabilized platform technology.

Airport security
Airport security normally requires baggage checks, metal screenings of individual persons, and rules against any object that could be used as a weapon. Since the September 11 attacks and the Real ID Act of 2005, airport security has dramatically increased and gotten tighter and stricter than ever before.

Products and services
Most major airports provide commercial outlets for products and services. Most of these companies, many of which are internationally known brands, are located within the departure areas. These include clothing boutiques and restaurants and in the US amounted to $4.2 billion in 2015. Prices charged for items sold at these outlets are generally higher than those outside the airport. However, some airports now regulate costs to keep them comparable to "street prices". This term is misleading as prices often match the manufacturers' suggested retail price (MSRP) but are almost never discounted.

Many new airports include walkthrough duty-free stores that require air passengers to enter a retail store upon exiting security. Airport planners sometimes incorporate winding routes within these stores such that passengers encounter more goods as they walk towards their gate. Planners also install artworks next to the airport's shops in order to draw passengers into the stores.

Apart from major fast food chains, some airport restaurants offer regional cuisine specialties for those in transit so that they may sample local food without leaving the airport.

Some airport structures include on-site hotels built within or attached to a terminal building. Airport hotels have grown popular due to their convenience for transient passengers and easy accessibility to the airport terminal. Many airport hotels also have agreements with airlines to provide overnight lodging for displaced passengers.

Major airports in such countries as Russia and Japan offer miniature sleeping units within the airport that are available for rent by the hour. The smallest type is the capsule hotel popular in Japan. A slightly larger variety is known as a sleep box. An even larger type is provided by the company YOTEL.

Some airports provide smoking areas and prayer areas.

Premium and VIP services
Airports may also contain premium and VIP services. The premium and VIP services may include express check-in and dedicated check-in counters. These services are usually reserved for first and business class passengers, premium frequent flyers, and members of the airline's clubs. Premium services may sometimes be open to passengers who are members of a different airline's frequent flyer program. This can sometimes be part of a reciprocal deal, as when multiple airlines are part of the same alliance, or as a ploy to attract premium customers away from rival airlines.

Sometimes these premium services will be offered to a non-premium passenger if the airline has made a mistake in handling of the passenger, such as unreasonable delays or mishandling of checked baggage.

Airline lounges frequently offer free or reduced cost food, as well as alcoholic and non-alcoholic beverages. Lounges themselves typically have seating, showers, quiet areas, televisions, computer, Wi-Fi and Internet access, and power outlets that passengers may use for their electronic equipment. Some airline lounges employ baristas, bartenders and gourmet chefs.

Airlines sometimes operate multiple lounges within the one airport terminal allowing ultra-premium customers, such as first class customers, additional services, which are not available to other premium customers. Multiple lounges may also prevent overcrowding of the lounge facilities.

Cargo and freight service
In addition to people, airports move cargo around the clock. Cargo airlines often have their own on-site and adjacent infrastructure to transfer parcels between ground and air.

Cargo Terminal Facilities are areas where international airports export cargo has to be stored after customs clearance and prior to loading the aircraft. Similarly, import cargo that is offloaded needs to be in bond before the consignee decides to take delivery. Areas have to be kept aside for examination of export and import cargo by the airport authorities. Designated areas or sheds may be given to airlines or freight forward ring agencies.

Every cargo terminal has a landside and an airside. The landside is where the exporters and importers through either their agents or by themselves deliver or collect shipments while the airside is where loads are moved to or from the aircraft. In addition, cargo terminals are divided into distinct areas – export, import, and interline or transshipment.

Access and onward travel
Airports require parking lots, for passengers who may leave the cars at the airport for a long period of time. Large airports will also have car-rental firms, taxi ranks, bus stops and sometimes a train station.

Many large airports are located near railway trunk routes for seamless connection of multimodal transport, for instance Frankfurt Airport, Amsterdam Airport Schiphol, London Heathrow Airport, Tokyo Haneda Airport, Tokyo Narita Airport, Hamad International Airport, London Gatwick Airport and London Stansted Airport. It is also common to connect an airport and a city with rapid transit, light rail lines or other non-road public transport systems. Some examples of this would include the AirTrain JFK at John F. Kennedy International Airport in New York, Link light rail that runs from the heart of downtown Seattle to Seattle–Tacoma International Airport, and the Silver Line T at Boston's Logan International Airport by the Massachusetts Bay Transportation Authority (MBTA). Such a connection lowers risk of missed flights due to traffic congestion. Large airports usually have access also through controlled-access highways ('freeways' or 'motorways') from which motor vehicles enter either the departure loop or the arrival loop.

Internal transport

The distances passengers need to move within a large airport can be substantial. It is common for airports to provide moving walkways, buses, and rail transport systems. Some airports like Hartsfield–Jackson Atlanta International Airport and London Stansted Airport have a transit system that connects some of the gates to a main terminal. Airports with more than one terminal have a transit system to connect the terminals together, such as John F. Kennedy International Airport, Mexico City International Airport and London Gatwick Airport.

Airport operations

Airport operations are made possible by an organized network of trained personnel, specialized equipment, and spatial data. After thousands of ground operations staff left the industry during the COVID-19 pandemic, there have been discussions on the need for systemic improvements in three primary areas:

 * Improving talent acquisition and retention
 * Implementing global standardizations
 * Digitizing and automating processes

The surfaces where ground operations occur are generally divided into three regions: runways, taxiways, and aprons.

Air traffic control
Air traffic control (ATC) is the task of managing aircraft movements and making sure they are safe, orderly and expeditious. At the largest airports, air traffic control is a series of highly complex operations that requires managing frequent traffic that moves in all three dimensions.

A "towered" or "controlled" airport has a control tower where the air traffic controllers are based. Pilots are required to maintain two-way radio communication with the controllers, and to acknowledge and comply with their instructions. A "non-towered" airport has no operating control tower and therefore two-way radio communications are not required, though it is good operating practice for pilots to transmit their intentions on the airport's common traffic advisory frequency (CTAF) for the benefit of other aircraft in the area. The CTAF may be a Universal Integrated Community (UNICOM), MULTICOM, Flight Service Station (FSS), or tower frequency.

The majority of the world's airports are small facilities without a tower. Not all towered airports have 24/7 ATC operations. In those cases, non-towered procedures apply when the tower is not in use, such as at night. Non-towered airports come under area (en-route) control. Remote and virtual tower (RVT) is a system in which ATC is handled by controllers who are not present at the airport itself.

Air traffic control responsibilities at airports are usually divided into at least two main areas: ground and tower, though a single controller may work both stations. The busiest airports may subdivide responsibilities further, with clearance delivery, apron control, and/or other specialized ATC stations.

Ground control
Ground control is responsible for directing all ground traffic in designated "movement areas", except the traffic on runways. This includes planes, baggage trains, snowplows, grass cutters, fuel trucks, stair trucks, airline food trucks, conveyor belt vehicles and other vehicles. Ground Control will instruct these vehicles on which taxiways to use, which runway they will use (in the case of planes), where they will park, and when it is safe to cross runways. When a plane is ready to takeoff it will be turned over to tower control. Conversely, after a plane has landed it will depart the runway and be "handed over" from Tower to Ground Control.

Tower control
Tower control is responsible for aircraft on the runway and in the controlled airspace immediately surrounding the airport. Tower controllers may use radar to locate an aircraft's position in 3D space, or they may rely on pilot position reports and visual observation. They coordinate the sequencing of aircraft in the traffic pattern and direct aircraft on how to safely join and leave the circuit. Aircraft which are only passing through the airspace must also contact tower control to be sure they remain clear of other traffic.

Traffic pattern
At all airports the use of a traffic pattern (often called a traffic circuit outside the US) is possible. They may help to assure smooth traffic flow between departing and arriving aircraft. There is no technical need within modern commercial aviation for performing this pattern, provided there is no queue. And due to the so-called SLOT-times, the overall traffic planning tend to assure landing queues are avoided. If for instance an aircraft approaches runway 17 (which has a heading of approx. 170 degrees) from the north (coming from 360/0 degrees heading towards 180 degrees), the aircraft will land as fast as possible by just turning 10 degrees and follow the glidepath, without orbit the runway for visual reasons, whenever this is possible. For smaller piston engined airplanes at smaller airfields without ILS equipment, things are very different though.

Generally, this pattern is a circuit consisting of five "legs" that form a rectangle (two legs and the runway form one side, with the remaining legs forming three more sides). Each leg is named (see diagram), and ATC directs pilots on how to join and leave the circuit. Traffic patterns are flown at one specific altitude, usually 800 or above ground level (AGL). Standard traffic patterns are left-handed, meaning all turns are made to the left. One of the main reason for this is that pilots sit on the left side of the airplane, and a Left-hand patterns improves their visibility of the airport and pattern. Right-handed patterns do exist, usually because of obstacles such as a mountain, or to reduce noise for local residents. The predetermined circuit helps traffic flow smoothly because all pilots know what to expect, and helps reduce the chance of a mid-air collision.

At controlled airports, a circuit can be in place but is not normally used. Rather, aircraft (usually only commercial with long routes) request approach clearance while they are still hours away from the airport; the destination airport can then plan a queue of arrivals, and planes will be guided into one queue per active runway for a "straight-in" approach. While this system keeps the airspace free and is simpler for pilots, it requires detailed knowledge of how aircraft are planning to use the airport ahead of time and is therefore only possible with large commercial airliners on pre-scheduled flights. The system has recently become so advanced that controllers can predict whether an aircraft will be delayed on landing before it even takes off; that aircraft can then be delayed on the ground, rather than wasting expensive fuel waiting in the air.

Navigational aids
There are a number of aids, both visual and electronic, though not at all airports. A visual approach slope indicator (VASI) helps pilots fly the approach for landing. Some airports are equipped with a VHF omnidirectional range (VOR) to help pilots find the direction to the airport. VORs are often accompanied by a distance measuring equipment (DME) to determine the distance to the VOR. VORs are also located off airports, where they serve to provide airways for aircraft to navigate upon. In poor weather, pilots will use an instrument landing system (ILS) to find the runway and fly the correct approach, even if they cannot see the ground. The number of instrument approaches based on the use of the Global Positioning System (GPS) is rapidly increasing and may eventually become the primary means for instrument landings.

Larger airports sometimes offer precision approach radar (PAR), but these systems are more common at military air bases than civilian airports. The aircraft's horizontal and vertical movement is tracked via radar, and the controller tells the pilot his position relative to the approach slope. Once the pilots can see the runway lights, they may continue with a visual landing.

Taxiway signs
Airport guidance signs provide direction and information to taxiing aircraft and airport vehicles. Smaller aerodromes may have few or no signs, relying instead on diagrams and charts.

Lighting
Many airports have lighting that help guide planes using the runways and taxiways at night or in rain or fog.

On runways, green lights indicate the beginning of the runway for landing, while red lights indicate the end of the runway. Runway edge lighting consists of white lights spaced out on both sides of the runway, indicating the edges. Some airports have more complicated lighting on the runways including lights that run down the centerline of the runway and lights that help indicate the approach (an approach lighting system, or ALS). Low-traffic airports may use pilot-controlled lighting to save electricity and staffing costs.

Along taxiways, blue lights indicate the taxiway's edge, and some airports have embedded green lights that indicate the centerline.

Weather observations
Weather observations at the airport are crucial to safe takeoffs and landings. In the United States and Canada, the vast majority of airports, large and small, will either have some form of automated airport weather station, whether an AWOS, ASOS, or AWSS, a human observer or a combination of the two. These weather observations, predominantly in the METAR format, are available over the radio, through automatic terminal information service (ATIS), via the ATC or the flight service station.

Planes take-off and land into the wind to achieve maximum performance. Because pilots need instantaneous information during landing, a windsock can also be kept in view of the runway. Aviation windsocks are made with lightweight material, withstand strong winds and some are lit up after dark or in foggy weather. Because visibility of windsocks is limited, often multiple glow-orange windsocks are placed on both sides of the runway.

Airport ground crew (ground handling)
Most airports have groundcrew handling the loading and unloading of passengers, crew, baggage and other services. Some groundcrew are linked to specific airlines.

Among the vehicles that serve an airliner on the ground are: The length of time an aircraft remains on the ground in between consecutive flights is known as "turnaround time". Airlines seek to minimize turnaround times, with times scheduled as low as 25 minutes.
 * A tow tractor to move the aircraft in and out of the berth.
 * A jet bridge (in some airports) or stairs unit to allow passengers to embark and disembark.
 * A ground power unit for supplying electricity. As the engines will be switched off, they will not be generating electricity as they do in flight.
 * A cleaning service.
 * A catering service to deliver food and drinks for a flight.
 * A toilet waste truck to empty the tank which holds the waste from the toilets in the aircraft.
 * A water truck to fill the water tanks of the aircraft.
 * A refueling vehicle. The fuel may come from a tanker, or from underground fuel tanks.
 * A conveyor belt unit for loading and unloading luggage.
 * A vehicle to transport luggage to and from the terminal.

Maintenance management
Like industrial equipment or facility management, airports require tailor-made maintenance management due to their complexity. With many tangible assets spread over a large area in different environments, these infrastructures must therefore effectively monitor these assets and store spare parts to maintain them at an optimal level of service.

To manage these airport assets, several solutions are competing for the market: CMMS (computerized maintenance management system) predominate, and mainly enable a company's maintenance activity to be monitored, planned, recorded and rationalized.

Safety management
Aviation safety is an important concern in the operation of an airport, and almost every airfield includes equipment and procedures for handling emergency situations. Airport crash tender crews are equipped for dealing with airfield accidents, crew and passenger extractions, and the hazards of highly flammable aviation fuel. The crews are also trained to deal with situations such as bomb threats, hijacking, and terrorist activities.

Hazards to aircraft include debris, nesting birds, and reduced friction levels due to environmental conditions such as ice, snow, or rain. Part of runway maintenance is airfield rubber removal which helps maintain friction levels. The fields must be kept clear of debris using cleaning equipment so that loose material does not become a projectile and enter an engine duct (see foreign object damage). In adverse weather conditions, ice and snow clearing equipment can be used to improve traction on the landing strip. For waiting aircraft, equipment is used to spray special deicing fluids on the wings.

Many airports are built near open fields or wetlands. These tend to attract bird populations, which can pose a hazard to aircraft in the form of bird strikes. Airport crews often need to discourage birds from taking up residence.

Some airports are located next to parks, golf courses, or other low-density uses of land. Other airports are located near densely populated urban or suburban areas.

An airport can have areas where collisions between aircraft on the ground tend to occur. Records are kept of any incursions where aircraft or vehicles are in an inappropriate location, allowing these "hot spots" to be identified. These locations then undergo special attention by transportation authorities (such as the FAA in the US) and airport administrators.

During the 1980s, a phenomenon known as microburst became a growing concern due to aircraft accidents caused by microburst wind shear, such as Delta Air Lines Flight 191. Microburst radar was developed as an aid to safety during landing, giving two to five minutes' warning to aircraft in the vicinity of the field of a microburst event.

Some airfields now have a special surface known as soft concrete at the end of the runway (stopway or blastpad) that behaves somewhat like styrofoam, bringing the plane to a relatively rapid halt as the material disintegrates. These surfaces are useful when the runway is located next to a body of water or other hazard, and prevent the planes from overrunning the end of the field.

Airports often have on-site firefighters to respond to emergencies. These use specialized vehicles, known as airport crash tenders. Most civil aviation authorities have required levels of on-site emergency response capabilities based on an airport's traffic. At airports where civil and military operations share a common set of runways and infrastructure, emergency response is often managed by the relevant military unit as part of their base's operations.

Environmental concerns and sustainability
Aircraft noise is a major cause of noise disturbance to residents living near airports. Sleep can be affected if the airports operate night and early morning flights. Aircraft noise occurs not only from take-offs and landings but also from ground operations including maintenance and testing of aircraft. Noise can have other health effects as well. Other noises and environmental concerns are vehicle traffic causing noise and pollution on roads leading to the airport.

The construction of new airports or addition of runways to existing airports, is often resisted by local residents because of the effect on countryside, historical sites, and local flora and fauna. Due to the risk of collision between birds and aircraft, large airports undertake population control programs where they frighten or shoot birds.

The construction of airports has been known to change local weather patterns. For example, because they often flatten out large areas, they can be susceptible to fog in areas where fog rarely forms. In addition, they generally replace trees and grass with pavement, they often change drainage patterns in agricultural areas, leading to more flooding, run-off and erosion in the surrounding land. Airports are often built on low-lying coastal land, globally 269 airports are at risk of coastal flooding now. A temperature rise of 2oC – consistent with the Paris Agreement - would lead to 100 airports being below mean sea level and 364 airports at risk of flooding. If global mean temperature rise exceeds this then as many as 572 airports will be at risk by 2100, leading to major disruptions without appropriate adaptation.

Some of the airport administrations prepare and publish annual environmental reports to show how they consider these environmental concerns in airport management issues and how they protect environment from airport operations. These reports contain all environmental protection measures performed by airport administration in terms of water, air, soil and noise pollution, resource conservation and protection of natural life around the airport.

A 2019 report from the Cooperative Research Programs of the US Transportation Research Board showed all airports have a role to play in advancing greenhouse gas (GHG) reduction initiatives. Small airports have demonstrated leadership by using their less complex organizational structure to implement newer technologies and to serve as a proving ground for their feasibility. Large airports have the economic stability and staff resources necessary to grow in-house expertise and fund comprehensive new programs.

A growing number of airports are installing solar photovoltaic arrays to offset their electricity use. The National Renewable Energy Lab has shown this can be done safely. This can also be done on the roofs of the airports and it has been found that the solar panels on these buildings work more effectively when compared to residential panels.

The world's first airport to be fully powered by solar energy is located at Kochi, India. Another airport known for considering environmental concerns is Seymour Airport in the Galapagos Islands.

As a part of their sustainability efforts, more and more airports are starting to explore the consequences of more electric aircraft coming into service. Electric aircraft need a lot of energy; operating 49 small 50 passenger short range battery electric aircraft would demand at least 16 GWh/year, and with short turnaround times between different flights, the charging powers have to be substantial. To tackle these issues, more airports are starting to look into alternative energy production such as solar power and wind power, but also how to use airport areas for biomass production. Another solution investigated is to use energy storage to charge during the night and use to charge the aircraft during daytime.

Airport hygiene and public health concerns
Airports, as major international travel hubs, have the potential to be significant transmission points for infectious diseases. A notable study conducted during the peak of the 2015–2016 flu season at Helsinki-Vantaa airport in Finland revealed that commonly touched surfaces in airports, especially the plastic security screening trays, are highly susceptible to contamination by respiratory viruses. These trays are touched by hundreds of passengers daily and, being made of plastic, a non-porous material, provide an environment where viruses can survive for extended periods. In comparison, bathroom surfaces in the same airport tested negative for respiratory viruses, possibly indicating a heightened awareness of hygiene in these spaces.

Hand hygiene plays a pivotal role in preventing the spread of infectious diseases in airports. Research indicates that only about 70% of individuals wash their hands after using the toilet, and of those, only 50% do so correctly. In airport settings, just one in five individuals maintain clean hands—defined as washing with soap for at least 15 seconds in the preceding hour. Given the frequent touching of shared surfaces in airports, such as trays, railings, and touch panels, this poses a significant risk for disease transmission. A study from the University of Cyprus and MIT used models and simulations to demonstrate that increasing hand cleanliness from 20% to 30% in all airports could reduce the potential global impact of a disease by 24%. If cleanliness levels reached 60%, this impact could decrease by 69%. Focusing on just the top 10 most influential airports for disease spread, enhancing hand hygiene practices could still significantly reduce disease transmission rates from 45% to 37%. The findings underscore the importance of promoting hand-washing in airports as a key measure in preventing the global spread of diseases.

Military air base
An airbase, sometimes referred to as an air station or airfield, provides basing and support of military aircraft. Some airbases, known as military airports, provide facilities similar to their civilian counterparts. For example, RAF Brize Norton in the UK has a terminal that caters to passengers for the Royal Air Force's scheduled flights to the Falkland Islands. Some airbases are co-located with civilian airports, sharing the same ATC facilities, runways, taxiways and emergency services, but with separate terminals, parking areas and hangars. Bardufoss Airport, Bardufoss Air Station in Norway and Pune Airport in India are examples of this.

An aircraft carrier is a warship that functions as a mobile airbase. Aircraft carriers allow a naval force to project air power without having to depend on local bases for land-based aircraft. After their development in World War I, aircraft carriers replaced the battleship as the centrepiece of a modern fleet during World War II.

Airport designation and naming
Most airports in the United States are designated "private-use airports" meaning that, whether publicly- or privately owned, the airport is not open or available for use by the public (although use of the airport may be made available by invitation of the owner or manager).

Airports are uniquely represented by their IATA airport code and ICAO airport code.

Most airport names include the location. Many airport names honour a public figure, commonly a politician (e.g., Charles de Gaulle Airport, George Bush Intercontinental Airport, Lennart Meri Airport, O.R. Tambo International Airport, Soekarno–Hatta International Airport), a monarch (e.g. Chhatrapati Shivaji International Airport, King Shaka International Airport), a cultural leader (e.g. Liverpool John Lennon Airport, Leonardo da Vinci-Fiumicino Airport, Louis Armstrong New Orleans International Airport) or a prominent figure in aviation history of the region (e.g. Sydney Kingsford Smith Airport), sometimes even famous writers (e.g. Allama Iqbal International Airport) and explorers (e.g. Venice Marco Polo Airport).

Some airports have unofficial names, possibly so widely circulated that its official name is little used or even known.

Some airport names include the word "International" to indicate their ability to handle international air traffic. This includes some airports that do not have scheduled international airline services (e.g. Port Elizabeth International Airport).

History and development
The earliest aircraft takeoff and landing sites were grassy fields. The plane could approach at any angle that provided a favorable wind direction. A slight improvement was the dirt-only field, which eliminated the drag from grass. However, these functioned well only in dry conditions. Later, concrete surfaces would allow landings regardless of meteorological conditions.

The title of "world's oldest airport" is disputed. Toussus-le-Noble airport near Paris was established in 1907 and has been operating since. College Park Airport in Maryland, US, established in 1909 by Wilbur Wright serves only general aviation traffic.

Beijing Nanyuan Airport in China, which was built to accommodate planes in 1904, and airships in 1907, opened in 1910. It was in operation until September 2019. Pearson Field Airport in Vancouver, Washington, United States, was built to accommodate planes in 1905 and airships in 1911, and is still in use as of February 2024.

Hamburg Airport opened in January 1911, making it the oldest commercial airport in the world which is still in operation. Bremen Airport opened in 1913 and remains in use, although it served as an American military field between 1945 and 1949. Amsterdam Airport Schiphol opened on September 16, 1916, as a military airfield, but has accepted civil aircraft only since December 17, 1920, allowing Sydney Airport—which started operations in January 1920—to claim to be one of the world's oldest continuously operating commercial airports. Minneapolis-Saint Paul International Airport in the US opened in 1920 and has been in continuous commercial service since. It serves about 35,000,000 passengers each year and continues to expand, recently opening a new 11,000-foot (3,355 m) runway. Of the airports constructed during this early period in aviation, it is one of the largest and busiest that is still currently operating. Don Mueang International Airport near Bangkok, Thailand, opened 1914, is also a contender, as well as the Rome Ciampino Airport, which opened in 1916. Increased aircraft traffic during World War I led to the construction of landing fields. Aircraft had to approach these from certain directions and this led to the development of aids for directing the approach and landing slope. Following the war, some of these military airfields added civil facilities for handling passenger traffic. One of the earliest such fields was Paris – Le Bourget Airport at Le Bourget, near Paris. The first airport to operate scheduled international commercial services was Hounslow Heath Aerodrome in August 1919, but it was closed and supplanted by Croydon Airport in March 1920. In 1922, the first permanent airport and commercial terminal solely for commercial aviation was opened at Flughafen Devau near what was then Königsberg, East Prussia. The airports of this era used a paved "apron", which permitted night flying as well as landing heavier aircraft.

The first lighting used on an airport was during the latter part of the 1920s; in the 1930s approach lighting came into use. These indicated the proper direction and angle of descent. The colours and flash intervals of these lights became standardized under the International Civil Aviation Organization (ICAO). In the 1940s, the slope-line approach system was introduced. This consisted of two rows of lights that formed a funnel indicating an aircraft's position on the glideslope. Additional lights indicated incorrect altitude and direction. After World War II, airport design became more sophisticated. Passenger buildings were being grouped together in an island, with runways arranged in groups about the terminal. This arrangement permitted expansion of the facilities. But it also meant that passengers had to travel further to reach their plane.

An improvement in the landing field was the introduction of grooves in the concrete surface. These run perpendicular to the direction of the landing aircraft and serve to draw off excess rainwater that could build up in front of the plane's wheels.

Airport construction boomed during the 1960s with the increase in jet aircraft traffic. Runways were extended out to 3000 m. The fields were constructed out of reinforced concrete using a slip-form machine that produces a continuous slab with no disruptions along the length. The early 1960s also saw the introduction of jet bridge systems to modern airport terminals, an innovation which eliminated outdoor passenger boarding. These systems became commonplace in the United States by the 1970s.

The malicious use of UAVs has led to the deployment of counter unmanned air system (C-UAS) technologies such as the Aaronia AARTOS which have been installed on major international airports.

Airports in entertainment
Airports have played major roles in films and television programs due to their very nature as a transport and international hub, and sometimes because of distinctive architectural features of particular airports. One such example of this is The Terminal, a film about a man who becomes permanently grounded in an airport terminal and must survive only on the food and shelter provided by the airport. They are also one of the major elements in movies such as The V.I.P.s, Speed, Airplane!, Airport (1970), Die Hard 2, Soul Plane, Jackie Brown, Get Shorty, Home Alone (1990), Home Alone 2: Lost in New York (1992), Liar Liar, Passenger 57, Final Destination (2000), Unaccompanied Minors, Catch Me If You Can, Rendition and The Langoliers. They have also played important parts in television series like Lost, The Amazing Race, America's Next Top Model (season 10), 90 Day Fiancé, Air Crash Investigation which have significant parts of their story set within airports. In other programmes and films, airports are merely indicative of journeys, e.g. Good Will Hunting.

Several computer simulation games put the player in charge of an airport. These include the Airport Tycoon series, SimAirport and Airport CEO.

Airport directories
Each civil aviation authority provides a source of information about airports in their country. This will contain information on airport elevation, airport lighting, runway information, communications facilities and frequencies, hours of operation, nearby NAVAIDs and contact information where prior arrangement for landing is necessary.
 * Australia
 * Information can be found on-line in the En route Supplement Australia (ERSA) which is published by Airservices Australia, a government owned corporation charged with managing Australian ATC.

 * Brazil
 * Infraero is responsible for the airports in Brazil

 * Canada
 * Two publications, the Canada Flight Supplement (CFS) and the Water Aerodrome Supplement, published by Nav Canada under the authority of Transport Canada provides equivalent information.

 * Europe
 * The European Organisation for the Safety of Air Navigation (EUROCONTROL) provides an Aeronautical Information Publication (AIP), aeronautical charts and NOTAM services for multiple European countries.

 * Germany
 * Provided by the Luftfahrt-Bundesamt (Federal Office for Civil Aviation of Germany).

 * France
 * Aviation Generale Delage edited by Delville and published by Breitling.

 * The United Kingdom
 * The information is found in Pooley's Flight Guide, a publication compiled with the assistance of the United Kingdom Civil Aviation Authority (CAA). Pooley's also contains information on some continental European airports that are close to Great Britain. National Air Traffic Services, the UK's Air Navigation Service Provider, a public–private partnership also publishes an online AIP for the UK.

 * The United States
 * The US uses the Airport/Facility Directory (A/FD) (now officially termed the Chart Supplement) published in seven volumes. DAFIF also includes extensive airport data but has been unavailable to the public at large since 2006.

 * Japan
 * Aeronautical Information Publication (AIP) is provided by Japan Aeronautical Information Service Center, under the authority of Japan Civil Aviation Bureau, Ministry of Land, Infrastructure, Transport and Tourism of Japan.

A comprehensive, consumer/business directory of commercial airports in the world (primarily for airports as businesses, rather than for pilots) is organized by the trade group Airports Council International.

title: Airport


text:
European Men's Handball Championship

The European Men's Handball Championship is the official competition for senior men's national handball teams of Europe and takes place every two years since 1994, in the even-numbered year between the World Championship. In addition to crowning the European champions, the tournament also serves as a qualifying tournament for the Olympic Games and World Championship. The most successful team is Sweden who have won five titles. Spain, however, have won most medals.

History
In 1946, the International Handball Federation was founded by eight European nations, and though non-European nations competed at the World Championships, the medals had always been taken by European nations. European Handball Federation is founded in 1991. At the same time (1995), the World Championship was changed from a quadrennial to a biannual event, and the European Handball Federation now began its own championship – which also acted as a regional qualifier for the World Championship.

1990s
The first championship was held in Portugal in June 1994. The host nation had not managed to qualify for any World Championship thus far, and they finished 12th and last after losing all six games, including 21–38 to Romania in the 11th-place play-off. Sweden became the first European champion after defeating Russia by 34–21 in the final, Russia's heaviest loss in their international history. Both teams had gone through the tournament without loss, but Sweden's fast breaks became the key in the final; they scored 14 of their 34 goals on fast breaks. Swedish middle back Magnus Andersson was named the event's best player and Russian left back Vasily Kudinov was top scorer with 50 goals.

Two years later, the championship moved to Spain, with the same format. This time, no team went through the group stage without giving up points, but Russia and Sweden were to face off once again; this time in the semi-final, and Russia got revenge with a 24–21 win in front of 650 spectators. In the other semi-final, the hosts beat Yugoslavia 27–23, before 7,500 spectators littered the arena in Sevilla to watch the hosts go down by one goal despite the efforts of Talant Dujshebaev, a Kyrgyz-born back player who had played for Russia in 1994 but who now turned out for Spain. Federal Republic of Yugoslavia participated for the first time and finished third.

In 1998 the Championship was held in Italy, whose appearance at the 1997 World Championship was their first (and to date, only) at the top level of international handball. Spain went through the first six matches of the tournament unbeaten, while their opponents Sweden had won the first four games before becoming the first team to lose to hosts Italy. However, in the final, Sweden were too strong and won by 25–23 after having led by 15–9 at half-time in front of 6,100 spectators in Bolzano.

2000s
Two years later, the Championship was held in the Croatian cities of Zagreb and Rijeka. By now, the Championship had been moved back to January in the middle of the European handball season. The Championship acted as an Olympic qualifier, and hosts Croatia, who had won the 1996 Olympics, needed to finish in the top five to qualify. They lost to Spain and drew with France in the group stage, which sent them into a fifth-place play-off with neighbours Slovenia. 10,000 spectators watched as Slovenia prevailed by one goal and qualified for the Sydney Games. The two teams who had won European Championships before, Sweden and Russia, qualified for the final – Sweden had won the group stage match 28–25, but Russia took a six-goal lead at half-time. Sweden came back to tie the game at full-time, and two 10-minute extra periods were required before Sweden won 32–31 after Magnus Wislander scored the deciding goal.

Three-time champions Sweden were the next to host the European Championship, in 2002. This was the first tournament with 16 teams, an expansion from 12 in the previous four instalments. The Swedes won their first seven matches, and had already qualified for the semi-finals when they lost 26–27 to Denmark, having led 17–11 at half time. In the other main round group, Iceland became the third Nordic team to qualify after defeating Germany in the final match, but both Denmark and Iceland were soundly beaten in the semi-finals – Denmark lost 23–28 to Germany, while Sweden defeated Iceland by 11 goals. Sweden thus qualified for their fourth final in five attempts, and in front of 14,300 spectators in Stockholm Globe, they came back from a one-goal deficit when Staffan Olsson equalised with five seconds to spare. Sweden had substituted their goalkeeper, and Florian Kehrmann replied with a goal in an empty net, but it was disallowed because the referees had not started play after the Swedish goal. In the extra time, Sweden held on, and could celebrate their fourth title.

Sweden's row of three successive Championships was broken in Slovenia in 2004, when Germany won despite not being touted as a medal candidate by news agency Deutsche Presse Agentur. Germany suffered an early defeat to Serbia and Montenegro, and qualified for the main round as the third and final team from their group, having drawn with France as well. However, as the favourites beat each other in Germany's main round group, Germany qualified for the semi-finals in first place from the six-team group. In the other group, Croatia, who won the other group, had not lost any of their first seven games, while Denmark also had four successive wins.

Croatia faced hosts Slovenia in the semi-final, and the clash of the two Balkan neighbours saw heightened security measures. 7,000 spectators in the Hall Tivoli saw that the hosts became the first team to beat Croatia in this tournament despite 12 goals from Croatian right winger Mirza Džomba who was reputed to be the best handball player in the world at the time. Denmark, who had reached their second successive semi-final, once again had to bow out at this stage, as they lost 20–22 to Germany in what was described as a "hard-fought victory." Germany won the final more convincingly; a 16–10 lead at half time was never squandered, as Slovenia only got within three goals in the second half, and eventually lost 25–30.

The 2006 tournament was held in Switzerland, in the cities of Basel, Bern, Lucerne, St Gallen and Zürich. France won the tournament, going through with one solitary loss – a 26–29 defeat to Spain in the preliminary round (where France trailed by eight goals at half-time). Defending champions Germany was also in this preliminary group, and this time taking one point through from the group stage would not be enough for Germany. Despite winning all three main round games, so did France and Spain, and those two teams qualified for the semi-finals from Group I. From the other group, Croatia qualified in first place after a 34–30 victory over Serbia and Montenegro in the last match. Later that evening, Denmark beat Russia and qualified for their third successive semi-final, one point behind Croatia. However, the Group II teams were both defeated by Group I teams, causing France and Spain to meet again in the final. In the third-place play-off, Croatia surprisingly lost to Denmark, while the final saw France prevail by eight goals to win their first European Championship

Norway was the host country for the 2008 tournament. Matches were played in Bergen, Drammen, Lillehammer, Stavanger and Trondheim. Croatia, Norway, Hungary and France won their preliminary groups, but two of the teams failed to utilise their advantage; Norway drew with Poland and lost to Slovenia, and needed to beat Croatia in the final match of the group stage. Instead, Ivano Balić scored the 23–22 goal with twenty seconds to spare, and only a late equaliser gave Norway third place in the group. Hungary, Spain and Germany had all gone through with two points from Group C, and Germany sealed their qualification with a two-goal win over Sweden in a match where a draw would have been enough for the Swedes. In the first semifinal Croatia played France in a game dominated by strong defense by both teams, with the Croats achieving a three-goal lead twice, only to see France come back strong. Croatia goalkeeper Mirko Alilović saved a shot from Nikola Karabatic with six seconds to go as Croatia won 24–23. Denmark came back from 7–12 down to beat Germany, despite the Germans equalising within the final minute, as Lars Christiansen slotted home a penalty shot with three seconds remaining. Croatia started off well in the final, scoring the first four goals, but with eight saves more from Denmark's keeper, Kasper Hvidt, Denmark won 24–20 and took their first major trophy.

Top scorers by tournament
The record-holder for scored goals in a single Euro Championship is Sander Sagosen. He scored 65 goals for Norway at the 2020 European Men's Handball Championship that took place in Austria, Sweden and Norway.

Most successful players
The table shows the most successful players at the European Championships. Players listed in bold are still active as of 2022. Players marked with an asterisk (*) have the additional distinction of having been elected championship MVP.

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: European Men's Handball Championship


text:
1994 European Men's Handball Championship

The 1994 European Men's Handball Championship was the inaugural edition of the tournament, held in Portugal from 3 to 12 June 1994, in the cities of Porto and Almada. Sweden won the tournament after defeating Russia in the final, while Croatia finished third.

Preliminary round
All times are local (UTC+1).

Top player awards

 * Most Valuable Player: 🇸🇪 Magnus Andersson (SWE)
 * Top Scorer : 🇷🇺 Vasily Kudinov (RUS), 50 goals

All Star Team

 * Goalkeeper: 🇸🇪 Tomas Svensson (SWE)
 * Right wing: 🇸🇪 Pierre Thorsson (SWE)
 * Right back: Jan Jørgensen
 * Centre back: 🇸🇪 Magnus Andersson (SWE)
 * Left back: 🇷🇺 Vasily Kudinov (RUS)
 * Left wing: 🇸🇪 Erik Hajas (SWE)
 * Pivot: 🇷🇺 Dmitri Torgovanov (RUS)

Source:.


text:
1996 European Men's Handball Championship

The 1996 European Men's Handball Championship was the second edition of the tournament and held in Spain from 24 May to 2 June 1996, in the cities of Ciudad Real and Seville. Russia won the tournament after defeating Spain in the final, while Yugoslavia finished third.

Preliminary round
All times are local (UTC+2).


text:
1998 European Men's Handball Championship

The 1998 European Men's Handball Championship was the third edition of the tournament and held in Italy from 29 May to 7 June 1998, in the cities of Meran and Bolzano. Sweden won the tournament after defeating Spain in the final, while Germany finished third.

Qualification
Note: Bold indicates champion for that year. Italic indicates host for that year.

Preliminary round
All times are local (UTC+2).

All-Star Team
Source: EHF


text:
2000 European Men's Handball Championship

The 2000 European Men's Handball Championship was the fourth edition of the tournament and was held in Croatia from 21 to 30 January 2000, in the cities of Zagreb and Rijeka. Sweden won the tournament after defeating Russia in the final, while Spain finished third.

Qualification
Note: Bold indicates champion for that year. Italic indicates host for that year.

Venues
Two Croatian cities were selected as hosts for the 2000 Championship:

Preliminary round
All times are local (UTC+1).

All-Star Team
Source: EHF

Top goalscorers
Source: EHF

Top goalkeepers
(minimum 20% of total shots received by team) Source: EHF

Shooting statistics
2003 research of Croatian kinesiologists on the efficiency of the shooting at the Championship summarized: "Almost half of all the shots performed (44.61%) were executed from the back-court players' positions (field shots). The winning teams were considerably more efficient in field shots and in 7m throws than the defeated ones - (43.20%) and (76.53%) as compared to (32.52%) and (65.76%), respectively. (...) The winning teams had more successful field shots, 6m-centre shots and wing shots, and fewer unsuccessful 6m-centre and field shots and 7m throws. Scoring efficiency from a distance and from the 6m line differentiates the successful teams (winners) from the unsuccessful (defeated) ones."


text:
2002 European Men's Handball Championship

The 2002 Men's European Handball Championship was the fifth edition of the tournament and took place from 25 January to 3 February 2002 in Sweden.

Qualification
Note: Bold indicates champion for that year. Italic indicates host for that year.

Preliminary round
All times are local (UTC+1).

Main round
Points gained in the preliminary round against teams that also qualified, were carried over.

All-Star Team
Source: EHF

Top goalscorers
Source: EHF

Top goalkeepers
(minimum 20% of total shots received by team) Source: EHF EHF


text:
Wine (software)

Wine is a free and open-source compatibility layer to allow application software and computer games developed for Microsoft Windows to run on Unix-like operating systems. Developers can compile Windows applications against WineLib to help port them to Unix-like systems. Wine is predominantly written using black-box testing reverse-engineering, to avoid copyright issues. No code emulation or virtualization occurs. Wine is primarily developed for Linux and macOS.

In a 2007 survey by desktoplinux.com of 38,500 Linux desktop users, 31.5% of respondents reported using Wine to run Windows applications. This plurality was larger than all x86 virtualization programs combined, and larger than the 27.9% who reported not running Windows applications.

History
Bob Amstadt, the initial project leader, and Eric Youngdale started the Wine project in 1993 as a way to run Windows applications on Linux. It was inspired by two Sun Microsystems products, Wabi for the Solaris operating system, and the Public Windows Initiative, which was an attempt to get the Windows API fully reimplemented in the public domain as an ISO standard but rejected due to pressure from Microsoft in 1996. Wine originally targeted 16-bit applications for Windows 3.x, but  focuses on 32-bit and 64-bit versions which have become the standard on newer operating systems. The project originated in discussions on Usenet in comp.os.linux in June 1993. Alexandre Julliard has led the project since 1994.

The project has proven time-consuming and difficult for the developers, mostly because of incomplete and incorrect documentation of the Windows API. While Microsoft extensively documents most Win32 functions, some areas such as file formats and protocols have no publicly or incomplete available specification from Microsoft, and Windows also includes undocumented low-level functions, undocumented behavior and obscure bugs that Wine must duplicate precisely in order to allow some applications to work properly. Consequently, the Wine team has reverse-engineered many function calls and file formats in such areas as thunking.

The Wine project originally released Wine under the same MIT License as the X Window System, but owing to concern about proprietary versions of Wine not contributing their changes back to the core project, work as of March 2002 has used the LGPL for its licensing.

Wine officially entered beta with version 0.9 on 25 October 2005. Version 1.0 was released on 17 June 2008, after 15 years of development. Version 1.2 was released on 16 July 2010, version 1.4 on 7 March 2012, version 1.6 on 18 July 2013, version 1.8 on 19 December 2015 and version 9.0 on 16 January 2024. Development versions are released roughly every two weeks.

Wine-staging is an independently maintained set of aggressive patches not deemed ready by WineHQ developers for merging into the Wine repository, but still considered useful by the wine-compholio fork. It mainly covers experimental functions and bug fixes. Since January 2017, patches in wine-staging begins to be actively merged into the WineHQ upstream as wine-compholio transferred the project to Alistair Leslie-Hughes, a key WineHQ developer. , WineHQ also provides pre-built versions of wine-staging.

Corporate sponsorship
The main corporate sponsor of Wine is CodeWeavers, which employs Julliard and many other Wine developers to work on Wine and on CrossOver, CodeWeavers' supported version of Wine. CrossOver includes some application-specific tweaks not considered suitable for the upstream version, as well as some additional proprietary components.

The involvement of Corel for a time assisted the project, chiefly by employing Julliard and others to work on it. Corel had an interest in porting WordPerfect Office, its office suite, to Linux (especially Corel Linux). Corel later cancelled all Linux-related projects after Microsoft made major investments in Corel, stopping their Wine effort.

Other corporate sponsors include Google, which hired CodeWeavers to fix Wine so Picasa ran well enough to be ported directly to Linux using the same binary as on Windows; Google later paid for improvements to Wine's support for Adobe Photoshop CS2. Wine is also a regular beneficiary of Google's Summer of Code program.

Valve works with CodeWeavers to develop Proton, a Wine-based compatibility layer for Microsoft Windows games to run on Linux-based operating systems. Proton includes several patches that upstream Wine does not accept for various reasons, such as Linux-specific implementations of Win32 functions. Valve's involvement in the development of Proton (and, thus, the improvement of Linux gaming) has helped to improve Wine compatibility with Windows games.

Design
The goal of Wine is to implement the Windows APIs fully or partially that are required by programs that the users of Wine wish to run on top of a Unix-like system.

Basic architecture
The programming interface of Microsoft Windows consists largely of dynamic-link libraries (DLLs). These contain a huge number of wrapper sub-routines for the system calls of the kernel, the NTOS kernel-mode program (ntoskrnl.exe). A typical Windows program calls some Windows DLLs, which in turn calls user-mode gdi/user32 libraries, which in turn uses the kernel32.dll (win32 subsystem) responsible for dealing with the kernel through system calls. The system-call layer is considered private to Microsoft programmers as documentation is not publicly available, and published interfaces all rely on subsystems running on top of the kernel. Besides these, there are a number of programming interfaces implemented as services that run as separate processes. Applications communicate with user-mode services through RPCs.

Wine implements the Windows application binary interface (ABI) entirely in user space, rather than as a kernel module. Wine mostly mirrors the hierarchy, with services normally provided by the kernel in Windows instead provided by a daemon known as the wineserver, whose task is to implement basic Windows functionality, as well as integration with the X Window System, and translation of signals into native Windows exceptions. Although Wineserver implements some aspects of the Windows kernel, it is not possible to use native Windows drivers with it, due to Wine's underlying architecture.

Libraries and applications
Wine allows for loading both Windows DLLs and Unix shared objects for its Windows programs. Its built-in implementation of the most basic Windows DLLs, namely NTDLL, KERNEL32, GDI32, and USER32, uses the shared object method because they must use functions in the host operating system as well. Higher-level libraries, such as WineD3D, are free to use the DLL format. In many cases users can choose to load a DLL from Windows instead of the one implemented by Wine. Doing so can provide functionalities not yet implemented by Wine, but may also cause malfunctions if it relies on something else not present in Wine.

Wine tracks its state of implementation through automated unit testing done at every git commit.

Graphics and gaming
While most office software does not make use of complex GPU-accelerated graphics APIs, computer games do. To run these games properly, Wine would have to forward the drawing instructions to the host OS, and even translate them to something the host can understand.

DirectX is a collection of Microsoft APIs for rendering, audio and input. As of 2019, Wine 4.0 contains a DirectX 12 implementation for Vulkan API, and DirectX 11.2 for OpenGL. Wine 4.0 also allows Wine to run Vulkan applications by handing draw commands to the host OS, or in the case of macOS, by translating them into the Metal API by MoltenVK.

 * XAudio
 * , Wine 4.3 uses the FAudio library (and Wine 4.13 included a fix for it) to implement the XAudio2 audio API (and more).

 * XInput and Raw Input
 * Wine, since 4.0 (2019), supports game controllers through its builtin implementations of these libraries. They are built as Unix shared objects as they need to access the controller interfaces of the underlying OS, specifically through SDL.

 * Direct2D
 * Wine 4.0 supports Direct2D 1.2.

Direct3D
Much of Wine's DirectX effort goes into building WineD3D, a translation layer from Direct3D and DirectDraw API calls into OpenGL. As of 2019, this component supports up to DirectX 11. As of 12 December 2016, Wine is good enough to run Overwatch with D3D11. Besides being used in Wine, WineD3D DLLs have also been used on Windows itself, allowing for older GPUs to run games using newer DirectX versions and for old DDraw-based games to render correctly.

Some work is ongoing to move the Direct3D backend to Vulkan API. Direct3D 12 support in 4.0 is provided by a "vkd3d" subproject, and WineD3D has in 2019 been experimentally ported to use the Vulkan API. Another implementation, DXVK, translates Direct3D 8, 9, 10, and 11 calls into Vulkan as well and is a separate project.

Wine, when patched, can alternatively run Direct3D 9 API commands directly via a free and open-source Gallium3D State Tracker (aka Gallium3D GPU driver) without translation into OpenGL API calls. In this case, the Gallium3D layer allows a direct pass-through of DX9 drawing commands which results in performance improvements of up to a factor of 2. As of 2020, the project is named Gallium.Nine. It is available now as a separate standalone package and no longer needs a patched Wine version.

User interface
Wine is usually invoked from the command-line interpreter:.

winecfg

There is the utility  that starts a graphical user interface with controls for adjusting basic options. It is a GUI configuration utility included with Wine. Winecfg makes configuring Wine easier by making it unnecessary to edit the registry directly, although, if needed, this can be done with the included registry editor (similar to Windows regedit).

Third-party applications

Some applications require more tweaking than simply installing the application in order to work properly, such as manually configuring Wine to use certain Windows DLLs. The Wine project does not integrate such workarounds into the Wine codebase, instead preferring to focus solely on improving Wine's implementation of the Windows API. While this approach focuses Wine development on long-term compatibility, it makes it difficult for users to run applications that require workarounds. Consequently, many third-party applications have been created to ease the use of those applications that do not work out of the box within Wine itself. The Wine wiki maintains a page of current and obsolete third-party applications.
 * Winetricks is a script to install some basic components (typically Microsoft DLLs and fonts) and tweak settings required for some applications to run correctly under Wine. It can fully automate the install of a number of applications and games, including applying any needed workarounds. Winetricks has a GUI. The Wine project will accept bug reports for users of Winetricks, unlike most third-party applications. It is maintained by Wine developer Austin English.
 * Q4Wine is an open GUI for advanced setup of Wine.
 * Wine-Doors is an application management tool for the GNOME desktop which adds functionality to Wine. Wine-Doors is an alternative to WineTools which aims to improve upon WineTools' features and extend on the original idea with a more modern design approach.
 * IEs4Linux is a utility to install all versions of Internet Explorer, including versions 4 to 6 and version 7 (in beta).
 * Wineskin is a utility to manage Wine engine versions and create wrappers for macOS.
 * PlayOnLinux is an application to ease the installation of Windows applications (primarily games). There is also a corresponding Macintosh version called PlayOnMac.
 * Lutris is an open-source application to easily install Windows games on Linux.
 * Bordeaux is a proprietary Wine GUI configuration manager that runs winelib applications. It also supports installation of third-party utilities, installation of applications and games, and the ability to use custom configurations. Bordeaux currently runs on Linux, FreeBSD, PC-BSD, Solaris, OpenSolaris, OpenIndiana, and macOS computers.
 * Bottles is an open-source graphical Wine prefix and runners manager for Wine based on GTK4+Libadwaita. It provides a repository-based dependency installation system and bottle versioning to restore a previous state.
 * WineGUI is a free and open-source graphical interface to manage Wine. It allows you to easily create Wine bottles and install Windows applications or games.

Functionality
[[File:History Of WineAppDB.gif|thumb|300px|App compatibility progress over time, according to Wine AppDB test results.

{{Legend|#ececec|Software works flawlessly}} {{Legend|#fff600|Software works flawlessly after configuration}} {{Legend|#c0c0c0|Minor problems with the software}} {{Legend|#fcba0a|Major problems with the software}} {{Legend|#999966|Completely non-functional software}}]] The developers of the Direct3D portions of Wine have continued to implement new features such as pixel shaders to increase game support. Wine can also use native DLLs directly, thus increasing functionality, but then a license for Windows is needed unless the DLLs were distributed with the application itself.

Wine also includes its own open-source implementations of several Windows programs, such as Notepad, WordPad, Control Panel, Internet Explorer, and Windows Explorer.

The Wine Application Database (AppDB) is a community-maintained on-line database about which Windows programs works with Wine and how well they work.

Backward compatibility
Wine ensures good backward compatibility with legacy Windows applications, including those written for Windows 3.1x. Wine can mimic different Windows versions required for some programs, going as far back as Windows 2.0. However, Windows 1.x and Windows 2.x support was removed from Wine development version 1.3.12. If DOSBox is installed on the system (see below on MS-DOS), Wine development version 1.3.12 and later nevertheless show the "Windows 2.0" option for the Windows version to mimic, but Wine still will not run most Windows 2.0 programs because MS-DOS and Windows functions are not currently integrated.

Backward compatibility in Wine is generally superior to that of Windows, as newer versions of Windows can force users to upgrade legacy Windows applications, and may break unsupported software forever as there is nobody adjusting the program for the changes in the operating system. In many cases, Wine can offer better legacy support than newer versions of Windows with "Compatibility Mode". Wine can run 16-bit Windows programs (Win16) on a 64-bit operating system, which uses an x86-64 (64-bit) CPU, a functionality not found in 64-bit versions of Microsoft Windows. WineVDM allows 16-bit Windows applications to run on 64-bit versions of Windows.

Wine partially supports Windows console applications, and the user can choose which backend to use to manage the console (choices include raw streams, curses, and user32). When using the raw streams or curses backends, Windows applications will run in a Unix terminal.

64-bit applications
Preliminary support for 64-bit Windows applications was added to Wine 1.1.10, in December 2008. , the support is considered stable. The two versions of Wine are built separately, and as a result only building wine64 produces an environment only capable of running x86-64 applications.

, Wine has stable support for a WoW64 build, which allows both 32-bit and 64-bit Windows applications to run inside the same Wine instance. To perform such a build, one must first build the 64-bit version, and then build the 32-bit version referencing the 64-bit version. Just like Microsoft's WoW64, the 32-bit build process will add parts necessary for handling 32-bit programs to the 64-bit build. This functionality is seen from at least 2010.

MS-DOS
Early versions of Microsoft Windows run on top of MS-DOS, and Windows programs may depend on MS-DOS programs to be usable. Wine does not have good support for MS-DOS, but starting with development version 1.3.12, Wine tries running MS-DOS programs in DOSBox if DOSBox is available on the system. Wine also attempts to run Windows 1.x/2.x programs in DOSBox, which will only work if Windows is installed inside DOSBox.

Winelib
Wine provides Winelib, which allows its shared-object implementations of the Windows API to be used as actual libraries for a Unix program. This allows for Windows code to be built into native Unix executables. Since October 2010, Winelib also works on the ARM platform.

Non-x86 architectures
Support for Solaris SPARC was dropped in version 1.5.26.

ARM, Windows CE, and Windows RT
Wine provides some support for ARM (as well as ARM64/AArch64) processors and the Windows flavors that run on it. , Wine can run ARM/Win32 applications intended for unlocked Windows RT devices (but not Windows RT programs). Windows CE support (either x86 or ARM) is missing, but an unofficial, pre-alpha proof-of-concept version called WineCE allows for some support.

Wine for Android

On 3 February 2013 at the FOSDEM talk in Brussels, Alexandre Julliard demonstrated an early demo of Wine running on Google's Android operating system.

Experimental builds of WINE for Android (x86 and ARM) were released in late 2017. It has been routinely updated by the official developers ever since. The default builds do not implement cross-architecture emulation via QEMU, and as a result ARM versions will only run ARM applications that use the Win32 API.

Microsoft applications
Wine, by default, uses specialized Windows builds of Gecko and Mono to substitute for Microsoft's Internet Explorer and .NET Framework. Wine has built-in implementations of JScript and VBScript. It is possible to download and run Microsoft's installers for those programs through winetricks or manually.

Wine is not known to have good support for most versions of Internet Explorer (IE). Of all the reasonably recent versions, Internet Explorer 8 for Windows XP is the only version that reports a usable rating on Wine's AppDB, out-of-the-box. However Google Chrome gets a gold rating (as of Wine 5.5-staging), and Microsoft's IE replacement web browser Edge, is known to be based on that browser (after switching from Microsoft's own rendering engine ). Winetricks offer auto-installation for Internet Explorer 6 through 8, so these versions can be reasonably expected to work with its built-in workarounds.

An alternative for installing Internet Explorer directly is to use the now-defunct IEs4Linux. It is not compatible with the latest versions of Wine, and the development of IEs4Linux is inactive.

Other versions of Wine
The core Wine development aims at a correct implementation of the Windows API as a whole and has sometimes lagged in some areas of compatibility with certain applications. Direct3D, for example, remained unimplemented until 1998, although newer releases have had an increasingly complete implementation.

CrossOver
CodeWeavers markets CrossOver specifically for running Microsoft Office and other major Windows applications, including some games. CodeWeavers employs Alexandre Julliard to work on Wine and contributes most of its code to the Wine project under the LGPL. CodeWeavers also released a new version called CrossOver Mac for Intel-based Apple Macintosh computers on 10 January 2007. Unlike upstream wine, CrossOver is notably able to run on the x64-only versions of macOS, using a technique known as "wine32on64".

As of 2012, CrossOver includes the functionality of both the CrossOver Games and CrossOver Pro lines therefore CrossOver Games and CrossOver Pro are no longer available as single products.

CrossOver Games was optimized for running Windows video games. Unlike CrossOver, it didn't focus on providing the most stable version of Wine. Instead, experimental features are provided to support newer games.

Proton
On 21 August 2018, Valve announced a new variation of Wine, named Proton, designed to integrate with the Linux version of the company's Steam software (including Steam installations built into their Linux-based SteamOS operating system and Steam Machine computers). Valve's goal for Proton is to enable Steam users on Linux to play games which lack a native Linux port (particularly back-catalog games), and ultimately, through integration with Steam as well as improvements to game support relative to mainline Wine, to give users "the same simple plug-and-play experience" that they would get if they were playing the game natively on Linux. Proton entered public beta immediately upon being announced.

Valve had already been collaborating with CodeWeavers since 2016 to develop improvements to Wine's gaming performance, some of which have been merged to the upstream Wine project. Some of the specific improvements incorporated into Proton include Vulkan-based Direct3D 9, 10, 11, and 12 implementations via vkd3d, DXVK, and D9VK multi-threaded performance improvements via esync, improved handling of fullscreen games, and better automatic game controller hardware support.

Proton is fully open-source and available via GitHub.

WINE@Etersoft
The Russian company Etersoft has been developing a proprietary version of Wine since 2006. WINE@Etersoft supports popular Russian applications (for example, 1C:Enterprise by 1C Company).

Other projects using Wine source code
Other projects using Wine source code include:
 * OTVDM, a 16-bit app compatibility layer for 64-bit Windows.
 * ReactOS, a project to write an operating system compatible with Windows NT versions 5.x and up (which includes Windows 2000 and its successors) down to the device driver level. ReactOS uses Wine source code considerably; however, due to architectural differences between ReactOS and Wine, ReactOS's code is not generally reused in Wine. For example, ReactOS specific DLLs, such as ntdll, user32, kernel32, gdi32, and advapi, cannot be used in Wine. In July 2009, Aleksey Bragin, the ReactOS project lead, started a new ReactOS branch called Arwinss, and it was officially announced in January 2010. Arwinss is an alternative implementation of the core Win32 components, and uses mostly unchanged versions of Wine's user32.dll and gdi32.dll.
 * WineBottler, a wrapper around Wine in the form of a normal Mac application. It manages multiple Wine configurations for different programs in the form of "bottles."
 * Wineskin, an open source Wine GUI configuration manager for macOS. Wineskin creates a wrapper around Wine in the form of a normal Mac Application. The wrapper can also be used to make a distributable "port" of software.
 * Odin, a project to run Win32 binaries on OS/2 or convert them to OS/2 native format. The project also provides the Odin32 API to compile Win32 programs for OS/2.
 * Virtualization products such as Parallels Desktop for Mac and VirtualBox use WineD3D to make use of the GPU.
 * WinOnX, a commercial package of Wine for macOS that includes a GUI for adding and managing applications and virtual machines.
 * WineD3D for Windows, a compatibility wrapper which emulates old Direct3D versions and features that were removed by Microsoft in recent Windows releases, using OpenGL. This sometimes gets older games working again.
 * Apple Game Porting Toolkit, a suite of software introduced at Apple's Worldwide Developer Conference in June 2023 to facilitate porting games from Windows to Mac.

Discontinued

 * Cedega / WineX: TransGaming Inc. (now Findev Inc. since the sale of its software businesses) produced the proprietary Cedega software. Formerly known as WineX, Cedega represented a fork from the last MIT-licensed version of Wine in 2002. Much like CrossOver Games, TransGaming's Cedega was targeted towards running Windows video games. On 7 January 2011, TransGaming Inc. announced continued development of Cedega Technology under the GameTree Developer Program. TransGaming Inc. allowed members to keep using their Cedega ID and password until 28 February 2011.
 * Cider: TransGaming also produced Cider, a library for Apple–Intel architecture Macintoshes. Instead of being an end-user product, Cider (like Winelib) is a wrapper allowing developers to adapt their games to run natively on Intel Mac without any changes in source code.
 * Darwine: a port of the Wine libraries to Darwin and Mac OS X for the PowerPC and Intel x86 (32-bit) architectures, created by the OpenDarwin team in 2004. Its PowerPC version relied on QEMU. Darwine was merged back into Wine in 2009.
 * E/OS LX: a project attempting to allow any program designed for any operating system to be run without the need to actually install any other operating system.
 * Pipelight: a custom version of Wine (wine-compholio) that acts as a wrapper for Windows NPAPI plugins within Linux browsers. This tool permits Linux users to run Microsoft Silverlight, the Microsoft equivalent of Adobe Flash, and the Unity web plugin, along with a variety of other NPAPI plugins. The project provides an extensive set of patches against the upstream Wine project, some of which were approved and added to upstream Wine. Pipelight is largely obsolete, as modern browsers no longer support NPAPI plugins and Silverlight has been deprecated by Microsoft.

Reception
The Wine project has received a number of technical and philosophical complaints and concerns over the years.

Security
Because of Wine's ability to run Windows binary code, concerns have been raised over native Windows viruses and malware affecting Unix-like operating systems as Wine can run limited malware made for Windows. A 2018 security analysis found that 5 out of 30 malware samples were able to successfully run through Wine, a relatively low rate that nevertheless posed a security risk. For this reason the developers of Wine recommend never running it as the superuser. Malware research software such as ZeroWine runs Wine on Linux in a virtual machine, to keep the malware completely isolated from the host system. An alternative to improve the security without the performance cost of using a virtual machine, is to run Wine in an LXC container, as Anbox software is doing by default with Android.

Another security concern is when the implemented specifications are ill-designed and allow for security compromise. Because Wine implements these specifications, it will likely also implement any security vulnerabilities they contain. One instance of this problem was the 2006 Windows Metafile vulnerability, which saw Wine implementing the vulnerable SETABORTPROC escape.

Wine vs. native Unix applications
A common concern about Wine is that its existence means that vendors are less likely to write native Linux, macOS, and BSD applications. As an example of this, it is worth considering IBM's 1994 operating system, OS/2 Warp. An article describes the weaknesses of OS/2 which killed it, the first one being:

"OS/2 offered excellent compatibility with DOS and Windows 3.1 applications. No, this is not an error. Many application vendors argued that by developing a DOS or Windows app, they would reach the OS/2 market in addition to DOS/Windows markets and they didn't develop native OS/2 applications."

However, OS/2 had many problems with end user acceptance. Perhaps the most serious was that most computers sold already came with DOS and Windows, and many people didn't bother to evaluate OS/2 on its merits due to already having an operating system. "Bundling" of DOS and Windows and the chilling effect this had on the operating system market frequently came up in United States v. Microsoft Corporation.

The Wine project itself responds to the specific complaint of "encouraging" the continued development for the Windows API on one of its wiki pages: "For most people there remain a handful of programs locking them in to Windows. It's obvious there will never be a Microsoft Office ported to Linux, however older versions of programs like TurboTax won't be ported either. Similarly, there are tens of thousands of games and internal corporate applications which will never be ported. If you want to use Linux and rely on any legacy Windows application, something like Wine is essential... Wine makes Linux more useful and allows for millions of users to switch who couldn't otherwise. This greatly raises Linux marketshare, drawing more commercial and community developers to Linux."

Also, the Wine Wiki page claims that Wine can help break the chicken-and-egg problem for Linux on the desktop: "This brings us to the chicken and egg issue of Linux on the desktop. Until Linux can provide equivalents for the above applications, its market share on the desktop will stagnate. But until the market share of Linux on the desktop rises, no vendor will develop applications for Linux. How does one break this vicious circle? Again, Wine can provide an answer. By letting users reuse the Windows applications they have invested time and money in, Wine dramatically lowers the barrier that prevents users from switching to Linux. This then makes it possible for Linux to take off on the desktop, which increases its market share in that segment. In turn, this makes it viable for companies to produce Linux versions of their applications, and for new products to come out just for the Linux market. This reasoning could be dismissed easily if Wine was only capable of running Solitaire. However, now it can run Microsoft Office, multimedia applications such as QuickTime and Windows Media Player, and even games such as Max Payne or Unreal Tournament 3. Almost any other complex application can be made to run well given a bit of time. And each time that work is done to add one application to this list, many other applications benefit from this work and become usable too. Have a look at our Application Database to get an idea on what can be run under Wine."

The use of Wine for gaming has proved specifically controversial in the Linux community, as some feel it is preventing, or at least hindering, the further growth of native Linux gaming on the platform. One quirk however is that Wine is now able to run 16-bit and even certain 32-bit applications and games that do not launch on current 64-bit Windows versions. This use-case has led to running Wine on Windows itself via Windows Subsystem for Linux or third-party virtual machines, as well as encapsulated by means such as BoxedWine and Otvdm.

Microsoft
Until 2020, Microsoft had not made any public statements about Wine. However, the Windows Update online service will block updates to Microsoft applications running in Wine. On 16 February 2005, Ivan Leo Puoti discovered that Microsoft had started checking the Windows Registry for the Wine configuration key and would block the Windows Update for any component. As Puoti noted: "It's also the first time Microsoft acknowledges the existence of Wine."

In January 2020, Microsoft cited Wine as a positive consequence of being able to reimplement APIs, in its amicus curiae brief for Google LLC v. Oracle America, Inc.

title: Wine (software)