Abstract We report on the status, technology, and physics reach of Borexino, which will directly measure the 862 keV 7 Be neutrinos from the sun. This will be a powerful probe of all currently allowed solar neutrino oscillation parameters, as well as an important test of our basic understanding of solar neutrino physics. The primary challenge of the experiment, which has dictated the design of the detector, is achieving an unprecedented low level of radioactivity. Filling and commissioning of the detector is expected to being in the summer of this year.