Observations of Type Ia supernovae have led to the conclusion that the Universe is expanding at an accelerated rate and that it is filled with a dark energy that dominates its energy content. These extraordinary conclusions are founded on empirical evidence. Further observations are required to reduce the uncertainties, and comprehensive theoretical and computational studies are needed to provide a foundation for these observations. What are the progenitors for this supernova class? What is the supernova mechanism? What is the origin of the width-luminosity relationship? What are the similarities and differences between nearby and distant supernovae? These are some of the key questions being addressed.

The mechanism for core collapse supernovae remains elusive. Only recently have spherically symmetric models achieved a sufficient level of sophistication to eliminate past model uncertainties and lay a good foundation for two- and three-dimensional models. And two- and three-dimensional modeling is only now beginning to reach a required level of realism to confidently delineate the role of convection and other fluid instabilities, rotation, and magnetic fields in supernova dynamics. The availability of TeraScale computing platforms has played a major role in the birth of this new generation of models. Observations continue to disclose a wealth and continuum of phenomena that modeling efforts must explain---the recent discovery of anomalously energetic supernovae with characteristics both similar and dissimilar to ordinary supernovae and the association of some core collapse supernovae with gamma ray bursts are just two examples.

The origin of gamma ray bursts is still a mystery. The prevailing models involve core collapse supernovae and neutron star mergers, proposed to produce long (> 2 s) and short (< 2 s) GRBs, respectively. For a handful of long bursts, there is indeed observational evidence for a supernova connection, providing significant hints about the nature of the central engine, yet we are still a long way from realistic supernova models that can produce bursts. For the short burst class, the merger model requires significant development as well.

This program is intended to bring together supernova and gamma ray burst experts from both theory and observation to report on the latest developments; exchange ideas; promote new collaborations; plan new observations, experiments, and theoretical studies; and appropriately showcase supernova and gamma ray burst science. Supernova and gamma ray burst science provides a natural and exciting theme for this INT program. The overlap in modeling requirements to investigate both classes of supernovae and gamma ray bursts---i.e., the need to model multidimensional chemically reactive flows, radiation transport, and magnetohydrodynamics---and the proven fruitfulness of combining observational and theoretical expertise, provide additional compelling reasons for this program's organization.