We have used the beam–foil technique to measure mean lives for 16 transitions in F I–F IV in the wavelength region 400 Å–1000 Å. Good agreement is found with the results of recent calculations, particularly those employing correlated wave functions. The f-value trends for 5 isoelectronic sequences are presented in detail (2p52P0–2p43s2 D and 2p52P0–2p43s 2P in F I; 2p43P–2p33s 3D0 in F II; 2p32D0–2s2p42D and 2p34S0–2s2p44P in F III). Our f value for the 955 Å multiplet in F I is also used in conjunction with some new satellite data to show that the fluorine abundance is apparently depleted in interstellar clouds by a factor of at least 3 below its solar value.