The talks will cover core collapse supernovae and gamma-ray bursts. The evolution of massive stars leading to core collapse will be discussed. Attention will be paid to how the stellar properties depend on initial mass and on the presence of a binary companion. The observed properties of supernovae will be related to the expectations from stellar evolution. The evidence relating gamma-ray bursts to core collapse supernovae will be presented. Mechanisms for the explosion of supernovae will be discussed; there is not currently a consensus view that is accepted. Regardless of the explosion mechanism, the physical processes in the aftermath of the explosion are fairly well understood. However, the interaction of the central compact object with its surroundings remains an uncertain area. The exploding supernova initially expands into mass loss from the progenitor star, providing addition diagnostics of the event. If a central pulsar is present, it drives a shell into the inner part of the supernova ejecta. In the case of gamma-ray bursts, the interaction with the surroundings is observed as nonthermal, afterglow emission. There are still problems in reconciling the afterglow properties with expectations for the surroundings of massive stars.