  We review the recent measurements of the rare pion decays: Pi+ -> Pi0 e+ Nu
[pion beta, Pi_(e3), or Pi_beta decay], radiative decay Pi+ -> e+ Nu Gamma
[Pi_(e2Gamma) or RPD], and Pi+ -> e+ Nu [Pi_(e2)] decay, as well as the
radiative muon decay, Mu -> e Nu Nu-bar Gamma, their theoretical implications,
and prospects for further improvement.
