Supernovae destroy their progenitor stars, but their shocks may induce star formation; they remove matter from cosmic evolution inside their compact remnants, but they also enrich the universe with heavy elements and cosmic rays; they destroy surrounding dust but they may create dust as well (and may destroy it again). Core-collapse supernovae from massive progenitor stars have started doing this within a couple of million years since the first stars formed. I will present and discuss some recent and new results regarding the creative and destructive behaviour of supernovae, using examples of supernova remnants in the Magellanic Clouds and concentrating on infrared and radio observations.