We review the current observational status and theoretical interpretations for the class of broad lines type Ic supernovae. They are characterized by fast photospheric expansion and lack of H and He absorption. They have a larger than normal energy budget, suggesting that they are powered or, at least, augmented by a central engine, like a magnetar or an accreting black hole. There appears therefore to be a link between these supernovae and long-duration gamma-ray bursts. However, its nature has not been satisfactorily demystified.
- Gamma-ray bursts