F90 or F-90 may refer to: Science and technology Alacrite, a cobalt-based alloy also known as F90 Beechcraft King Air F90, a twin engine turboprop airplane BMW M5 (F90), a 6th generation of high performance variant of the BMW 5 Series Fortran 90, a computer programming language Hyperkinetic disorder (ICD-10 code) Nikon F90, a 35mm SLR camera Military Lockheed XF-90 F90 assault rifle, an assault rifle by Thales Australia, a development of the Steyr AUG assault rifle Other uses F-90 (comics), a fictional likeness of the Lockheed XF-90