Supernovae: Individual -- A Decade of Radio and X-ray Observations of SN 1993J -- Imaging of SN 1993J -- Nine Years of VLBI Imaging of Supernova 1993J -- On the SN 1993J Radio Shell Structure -- Optical, Ultraviolet, and Infrared Observations of SN 1993J -- Simulated Radio Images and Light Curves of SN 1993J -- X-ray Observations of SN 1993J -- Modeling the Radio and X-ray Emission of SN 1993J and SN 2002ap -- Detection of the Binary Companion to the Progenitor of SN 1993J -- Supernova 1987A: The Birth of a Supernova Remnant -- SN 1987A at Radio Wavelengths -- High-Resolution Radio Imaging of Young Supernovae: SN 1979C, SN 1986J, and SN 2001gd -- VLBI Observations of SN 1979C and SN 1986J -- SN 1994W: Evidence of Explosive Mass Ejection a Few Years Before Explosion -- A Most Energetic Type Ic Supernova: SN 2003L -- Radio Monitoring of Supernova 2001ig: The First Year -- Synthetic Spectra of the Type Ia SN 2002bo -- Supernovae: Observations -- Radio Supernovae -- Low Frequency Radio and X-ray Properties of Core-Collapse Supernovae -- Supernova Spectra -- Optical Spectroscopy of Type Ia Supernovae -- The Early Spectroscopy of Supernovae -- Optical Light Curves of Supernovae -- Late Light Curves of Type Ia SNe -- Photometric Observations of Recent Supernovae -- Observational Properties of Type II Plateau Supernovae -- X-ray Spectra of Young Supernovae -- Supernovae: Progenitors/Remnants -- Pre-Supernova Evolution of Rotating Massive Stars -- Radiation Bursts from a Presupernova Collapsar -- Radio Observations of Supernova Remnants in the M82 Starburst -- Deep Radio Imaging with MERLIN of the Supernova Remnants in M82 -- Thermonuclear Supernova Explosions and Their Remnants: The Case of Tycho -- Supernovae: Models -- Models of Supernova Explosions: Where Do We Stand? -- Core-Collapse Supernovae at the Threshold -- Two New Possible Mechanisms of Supernova-Like Explosions -- Tests for Supernova Explosion Models: from Light Curves to X-ray Emission of Supernova Remnants -- Understanding Type II Supernovae -- Magnetorotational Mechanism of Supernova Type II Explosion -- Nucleosynthesis in Black-Hole-Forming Supernovae -- Nucleosynthesis in Multi-Dimensional Simulations of SNII -- 56Ni Mass in Type IIP SNe: Light Curves and H? Luminosity Diagnostics -- Effects of Small-Scale Fluctuations of Neutrino Flux in Supernova Explosions -- Neutrino Gas in Equilibrium with Self-Interaction -- Weak Interaction Processes in Core-Collapse Supernovae -- Synthetic Spectra for Type Ia Supernovae at Early Epochs -- On the Stability of Thermonuclear Burning Fronts in Type Ia Supernovae -- Explosion Models for Thermonuclear Supernovae Resulting from Different Ignition Conditions -- Supernovae: Searches/Statistics -- Supernova Statistics -- The Infrared Supernova Rate -- The Rate and the Origin of Type Ia SNe in Radio Galaxies -- Supernovae in Galaxy Clusters -- Using Multi-Band Photometry to Classify Supernovae -- Supernova and Gamma-Ray Burst Connections -- Optical and Near-IR Observations of SN 1998bw -- SN 1998bw and Other Hyperenergetic Type Ic Supernovae -- The Supernova/GRB Connection -- Optical Bumps in Cosmological GRBs as Supernovae -- Long GRBs and Supernovae from Collapsars -- How Common are Engines in Ib/c Supernovae? -- Gamma-Ray Bursters -- Cosmic Gamma-Ray Bursts: The Big Picture -- The Surroundings of Gamma-Ray Bursts: Constraints on Progenitors -- The Radio Afterglows of Gamma-Ray Bursts -- Gamma-ray Bursts -- X-ray Emission from Gamma-Ray Bursts -- Particle Acceleration in Gamma-Ray Bursts -- The First Steps in the Life of a GRB -- Physical Restrictions to Cosmological Gamma-Ray Burst Models -- Dynamical Evolution of ?-cooled Disks Following Compact Binary Mergers -- On the Central Engine of Short Gamma-ray Bursts -- Supernovae, Gamma-Ray Bursters, and Cosmology -- The Expanding and Accelerating Universe -- Observations of Type Ia Supernovae and Challenges for Cosmology -- The Standard Candle Method for Type II Supernovae and the Hubble Constan -- Observing the First Stars, One Star at a Time -- The Host Galaxies of High-Redshift Type Ia Supernovae -- Constraints on SN Ia Progenitors and ICM Enrichment from Field and Cluster SN Rates -- Expected Changes of SNe with Redshift due to Evolution of Their Progenitors -- Dark Energy: Nature and Robustness -- Brane Universes Tested by Supernovae -- A Geometric Determination of the Distance to SN 1987A and the LMC.The proceedings of the conference Supernovae 2003 (IAU colloquium 192) provides an extensive state-of-the-art survey of all theoretical and observational aspects of supernovae and gamma-ray bursts, as well as their impact on cosmology. This volume offers everyone working in this field an authoritative and comprehensive source of reference.