  The Generalized Chiral Perturbation Theory enlarges the framework of the
standard $\chi$PT, relaxing certain assumptions which do not necessarily follow
from QCD or from experiment, and which are crucial for the usual formulation of
the low energy expansion. In this way, experimental tests of the foundations of
the standard $\chi$PT become possible. Emphasis is put on physical aspects
rather than on formal developements of G$\chi$PT.
