The FN P90, also known as the FN Project 1990, is a compact personal defense weapon (PDW) designed and manufactured by FN Herstal in Belgium. Created in response to NATO requests for a replacement for 9x19mm Parabellum firearms, the P90 was designed as a compact but powerful firearm for vehicle crews, operators of crew-served weapons, support personnel, special forces, and counter-terrorist groups. Designed in conjunction with the FN Five-seven pistol and FN 5.7x28mm ammunition, development of the weapon began in 1986, and production commenced in 1990 (from which the "90" in its name is derived), whereupon the 5.7x28mm ammunition was redesigned and shortened. A modified version of the P90 with a magazine adapted to use the new ammunition was introduced in 1993, and the Five-seven pistol was subsequently introduced as a companion weapon using the same 5.7x28mm ammunition. Featuring a compact bullpup design with an integrated reflex sight and fully ambidextrous controls, the P90 is an unconventional weapon with a futuristic appearance. Its design incorporates several innovations such as a unique top-mounted magazine and FN's small-caliber, high-velocity 5.7x28mm ammunition. Additional integrated features include interchangeable visible or infrared laser and tritium light source. [1]