X2

X2 may refer to:

Computers

 * X2 (protocol), a pre-V.90 standard for 56k downstream modem communications
 * Athlon 64 X2, the first dual-core desktop CPU manufactured by AMD
 * A two-lane PCI Express, slot
 * A type of 10 Gigabit Ethernet, optical transceiver
 * X2, a transport interface used to connect enodeBs in a LTE/4G network

Aircraft, spacecraft and rockets

 * Bell X-2, an experimental supersonic aircraft
 * Mitsubishi X-2 Shinshin, a Japanese experimental stealth fighter (formerly known as ATD-X)
 * Orba, also known as X-2, a planned British satellite
 * Sikorsky X2, a prototype, coaxial high-speed helicopter
 * Skycycle X-2, a rocket used by Evel Knievel
 * SpaceShipOne flight 17P, also known as X2, the second Ansari X Prize flight
 * X-2 Dragonfly, the company designation of the Rotor-Craft XR-11 experimental helicopter of the late 1940s
 * X-2 Rocket, the spacecraft used in Mission: Space in Epcot Center, Orlando, Florida

Watercraft

 * Bathyscaphe Trieste II, also known as X-2, the US Navy bathyscaphe based on the Trieste
 * HMS X2, a Royal Navy submarine
 * Kawasaki X2, a personal water craft

Other vehicles and transportation

 * BMW X2, a SUV vehicle produced by BMW
 * North Wing Sport X2, an American ultralight trike design
 * SJ X2, used for the X 2000 train system in Sweden
 * X2 (New York City bus), a bus route
 * X2, a Metrobus route, in Washington, D.C.

Video games

 * Dance Dance Revolution X2, a 2010 music video game for the PlayStation 2
 * Final Fantasy X-2, a 2003 role-playing video game
 * Mega Man X2, a 1994 platform game
 * X2: The Threat, a 2003 space simulation game
 * X2 (video game), a 1997 video game
 * X2, the main character in Star Wars Battlefront: Elite Squadron

Film

 * X2 (film), a 2003 sequel to the 2000 film X-Men
 * XXX: State of the Union, also known as X2 or xXx²: The Next Level, a 2005 American film

Phones

 * Nokia X2, feature phone/smartphone
 * Sendo X2, a Series 60 mobile phone
 * Sony Ericsson Xperia X2, smartphone

Other

 * X2 (roller coaster), at Six Flags Magic Mountain
 * Chi-squared distribution, a theoretical probability distribution in inferential statistics
 * Square (algebra), also known as the algebraic square
 * Keyboard sold by Korg in the 1990s
 * X-2 Counter Espionage Branch, counterintelligence branch of the Office of Strategic Services