  Recent progress is reviewed in four areas where new experimental data have
been obtained: proton-proton bremsstrahlung, threshold pion production in
proton-proton collisions, elastic electron-deuteron scattering and deuteron
photodisintegration at several GeV photon energy. Relativistic effects are
expected to be significant in these processes. High energy photodisintegration
suggests that partonic behavior could be relevant in subamplitudes at large
momentum transfer.
