The FN P90 is a selective fire personal defense weapon (PDW) designed and manufactured by FN Herstal in Belgium. The P90's name is an abbreviation of FN's Project 9.0—the weapon was created in response to NATO requests for a replacement for 9x19mm Parabellum firearms. It was designed as a compact but powerful firearm for vehicle drivers, operators of crew-served weapons, support personnel, special forces and counter-terrorist groups.
The P90 has a compact bullpup design and ambidextrous controls. It features several innovations such as the top-mounted magazine and FN's high velocity 5.7x28mm ammunition. The P90 was developed between 1986 and 1990. A P90 TR variant was then introduced in 1999, featuring a triple rail interface system for mounting accessories. Since 2005, the P90 has also been offered to civilian shooters as the PS90, a semi-automatic sporting version with a lengthened barrel.
By 2003, the P90 was in use with military and police forces in over 25 countries worldwide. In the United States, the P90 was in use with over 200 law enforcement agencies by 2009. The PS90 sporting model has also become popular with civilian shooters in the United States.