  After a short status report on chiral perturbation theory, I review recent
progress in determining some of the low-energy couplings by matching the
effective theory to QCD. Consequences for K_{l3} decays and for the extraction
of the CKM matrix element V_{us} are reported. Hadronic vacuum polarization at
low energies and its impact on the anomalous magnetic moment of the muon are
discussed.
