  In this talk I will review the recently published results by the A2 and
CB-TAPS Collaborations at MAMI on neutral pion photoproduction in the
near-threshold region. The combined measurement of the differential cross
section and the photon beam asymmetry with low statistical errors allowed for a
precise determination of the energy dependence of the real parts of the S- and
P-wave amplitudes for the first time, providing the most stringent test to date
of the predictions of Chiral Perturbation Theory and its energy region of
agreement with experiment.
