Partitioning and Transmutation (P&T) techniques could contribute to reduce the radioactive inventory and its associated radio-toxicity. Sub-critical Accelerator Driven Systems (ADS) are potential candidates as dedicated transmutation systems, and thus their development and more particularly the spallation target, is a relevant R&D topic. Thus, the MEGAwatt PIlot Experiment (MEGAPIE) (1 MW) was initiated in 1999 in order to design and build a liquid lead-bismuth spallation target, then to operate it into the Swiss spallation neutron facility SINQ at Paul Scherrer Institute (PSI). Many studies, carried out by the project partners addressed specific critical issues in the fields of neutronics, materials, thermal hydraulics, mass and heat transfer, structure mechanics and liquid metal technology, using analytical, numerical and experimental approaches. Moreover, it was necessary to perform safety and reliability assessments in order to demonstrate the integrity and operability of the target; and thus to develop the licensing process. The target has been built in France then shipped to Switzerland : in order to demonstrate the target characteristics and safe operability prior to irradiation foreseen in 2006, the target has been installed in PSI Test facility, fitted with all the ancillary systems, then tested off-beam. The already performed steps, conceptual and engineering design, manufacturing and assembly, safety and reliability assessment, integral tests have brought to ADS Community a unique relevant design and out-off beam operational feedback. The target is now installed in the SINQ facility, ready to be irradiated. The following steps : Irradiation, decommissioning, post irradiation experiments and waste management will complete the feedback from this unique experiment.