An accurate determination of the density profile at the plasma edge is of great importance for the understanding of H-mode transport barrier physics, as well as for the general characterisation of edge properties under plasma scenarios ranging from ELM-free H-modes to advanced tokamak concepts. Lithium beams have been successfully applied to this end on AS-DEX Upgrade, W7-AS, TEXTOR and JET, whereby the deconvolution of the Li(2p) light profile along the beam yields density profiles with high spatial and temporal resolution. Recent modifications of the Li-ion gun and neutralization cell on JET have lead to an increased reliability and performance. Furthermore, calibration procedures for the transmission and radial calibration of the observation system have been developed. The diagnostic has been operated at JET successfully for more than 700 pulses.