(1) The properties of the Supernovae discovered in coincidence with long-duration Gamma-ray Bursts will be reviewed, and compared to those of SNe for which GRBs are not observed. The SNe associated with GRBs are of Type Ic, they are brighter than the norm, and show very broad absorption lines in their spectra, indicative of high expansion velocities and hence of large explosion kinetic energies. This points to a massive star origin, and to the birth of a black hole at the time of collapse. There is strong evidence for gross asymmetries in the SN ejecta. the observational evidence seems to suggest that GRB/SNe are more massive and energetic than XRF/SNe, and come from more massive stars. While for GRB/SNe the collapsar model is favoured, XRF/SNe may host magnetars.

(2) Forty years after their discovery and nearly 15 years after their localization and afterglow detection, Gamma-Ray Bursts (GRBs) are still top targets for observation from the local Universe to its edge (up to redshift 9), and represent a prime theoretical challenge. Their prompt gamma-ray emission outshines every other source in the sky in this band and their initial optical counterparts can be as bright as V = 5, i.e. many orders of magnitudes more luminous than a normal quasar. Their X-ray afterglows reveal the presence of complex engines, whose nature is still debated (black hole vs neutron star). The rapid panchromatic variability of GRBs and their afterglows engages astronomers in the organization of multiwavelength observing campaigns that include satellites and ground-based telescopes. I will review the state of the art of the observations and the problems that are still open.