  The Sudbury Neutrino Observatory (SNO) is capable of measuring simultaneously
the flux of electron-type neutrinos and the total flux of all active flavours
of neutrinos originating from the Sun. A model-independent test of neutrino
flavour transformation was performed by comparing these two measurements.
Assuming an undistorted neutrino energy spectrum, this transformation has been
definitively demonstrated in the pure D2O phase of the SNO experiment. In the
second phase with dissolved NaCl in the D2O, the total active solar neutrino
flux was measured without any assumption on the energy dependence of flavour
transformation. In this talk, results from these measurements, their physics
implications and the current status of the SNO experiment are presented.
