JET, the flagship of the European fusion programme has obtained far-reaching results in all domains of tokamak physics. Results on confinement (scaling laws, confinement regimes), fusion performance (including D /T mixture), Divertor aspects and external current drive are described placing the emphasis on the consequence for the future JET programme and for the design parameters of the next step. After completion of major enhancement of its in-vessel components, JET will address the problems of combining high performance operation with radiating divertors and investigate advanced tokamak scenarios using profile control.