Recent scientific and technical progress on JET is summarized. The scientific programme on JET over the last 2 years has benefited significantly from various technological developments: advanced real time tools, enhanced heating systems and several upgraded and new diagnostics. JET has also provided more technological input to ITER on questions related to the first wall, divertor and tritium technology. A dedicated Trace Tritium Campaign has delivered a wealth of data on transport and confinement of tritium and alpha particles from the fusion reaction. An enhancement programme is currently underway on JET, consisting of the implementation of an additional set of upgraded and new diagnostics and a further upgrade of the heating systems. This will allow JET to continue to contribute significantly in questions related to the construction and operational phase of ITER. (c) 2005 Elsevier B.V. All rights reserved.