A review of the experimental results of the spin dynamics of binary spin glass alloys obtained with the help of esr, nmr, muon precession. Gssbauer effect and neutron scattering techniques is given. The results may be consitently described in terms of a spectrum of relaxation times evolving continuously with temperature and extending from relatively short (T 'L 10-13s) to very long times (T*) at temperatures around and below the freezing temperature.