Results and perspectives of the solar neutrino experiment Borexino

Borexino is a massive, calorimetric, liquid scintillator detector aimed at the detection of low energy sub-MeV solar neutrinos, installed at the Gran Sasso Laboratory. After several years of construction, data taking started in May 2007, providing immediately incontrovertible evidence of the unprecedented radiopurity of the target mass, at the level required to ensure the successful detection of 7Be solar neutrinos, which was then announced in the 2007 summer. In this talk first the main technical characteristics of the detector will be highlighted, with special emphasis on the exceptional purity challenges successfully faced by the Collaboration, and afterwards the physics outputs reached so far will be carefully reported and illustrated, together with the perspectives for the future measurements that will complete the broad program of the experiment.