  This talk includes a short introduction to Chiral Perturbation Theory in the
meson sector concentrating on a number of recent developments. I discuss the
latest fit of the low-energy constants. Finite volume corrections are discussed
for the case with twisted boundary conditions for form-factors and first
results at two-loops for three flavours for masses. The last part discusses the
extension to other symmetry breaking patterns relevant for technicolour and
related theories as well as the calculation of leading logarithms to high loop
orders.
