  Chiral perturbation theory is the effective field theory of the strong
interactions at low energies. We will give a short introduction to chiral
perturbation theory for mesons and will discuss, as an example, the
electromagnetic polarizabilities of the pion. These have recently been
extracted from an experiment on radiative $\pi^+$ photoproduction from the
proton ($\gamma p\to \gamma \pi^+ n$) at the Mainz Microtron MAMI. Next we will
turn to the one-baryon sector of chiral perturbation theory and will address
the issue of a consistent power counting scheme. As examples of the
heavy-baryon framework we will comment on the extraction of the axial radius
from pion electroproduction and will discuss the generalized polarizabilities
of the proton. Finally, we will discuss two recently proposed manifestly
Lorentz-invariant renormalization schemes and illustrate their application in a
calculation of the nucleon electromagnetic form factors.
