Three new low-energy ion implanters have been developed at GNS Science over the past few years for doping and materials modification processes. Two of the ion implanters are interlinked providing the possibility of ion implanting two different ion species at the same time. Successful experiments have been performed with selenium and nitrogen into silicon for enhanced silicon nanostructure field emission. The terminal voltage of the implanters can be varied between 2 and 50 kV. The vacuum pressure in the target exchange chambers are typically 10^-8 mbar allowing clean implantations. Many ion implantations of the group at GNS Science have been performed into metals, semiconductors, polymers and other materials. The target temperature can be varied between -190 and 1200 °C. So far more than 30 different elements and isotopes have been implanted ranging from hydrogen to lead and including, ¹⁵N and ¹⁸O, calcium, cobalt, iron and sulphur. A new implanter has been recently commissioned at the ‘triple beam line’ of the 3 MV accelerator that allows for simultaneous ion implantation (e.g. Co and Sm into ZnO), electron beam annealing from the back side using a high current LaB₆ powered electron annealer (e.g. T=1000 °C) and RBS in the same chamber. Specific technical and scientific details of the ion implanters built at GNS Science are discussed.