Supernovae.- Historical Supernovae.- Classification of Supernovae.- Supernova Rates.- Optical Spectra of Supernovae.- Optical Light Curves of Supernovae.- X-Ray Supernovae.- Ultraviolet Supernovae.- Radio Supernovae.- Supernova Interaction with a Circumstellar Medium.- Measuring Cosmology with Supernovae.- Supernova 1987A.- Supernovae to ?-Ray Bursters.- SN1998bw and Hypernovae.- Supernovae and ?-Ray Bursters.- ?-Ray Bursters.- Observational Properties of Cosmic ?-Ray Bursts.- X-Ray Observations of ?-Ray Burst Afterglows.- Optical Observations of ?-Ray Burst Afterglows.- Radio Observations of ?-Ray Burst Afterglows.- Gamma-Ray Bursts: The Underlying Model.- Ambient Interaction Models for ?-Ray Burst Afterglows.- Cosmological Studies with ?-Ray Bursts.