Energetic products of heavy ion collisions

Products of heavy ion collisions with total energy greater than the beam energy per nucleon are discussed with emphasis on recent data in pion and high energy gamma production. In the case of pion production, recent data either close to the conservation of energy threshold and or with high mass beams has given much larger cross sections than can be explained by present models. This strong coherence is not evident in the gamma ray production data, partly because there still exist inconsistencies between the data sets from various experimental groups. Coulomb effects in pion production are also discussed