2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/7218Gamma-ray bursts are the most luminous and probably the most relativistic events in the universe. The last few years have seen a tremendous increase in our knowledge of these events, but the source of the bursts still remains elusive. I will summarise recent progress in this field with special emphasis on our understanding of the possible progenitor systems.Invited review "Superdense QCD matter and compact stars", Yerevan, Armenia, Sept. 2003; 20 pages; reference addedAstrophysicstext