  Many aspects of the progenitor systems, environments, and explosion dynamics
of the various subtypes of supernovae are difficult to investigate at
extragalactic distances where they are observed as unresolved sources.
Alternatively, young supernova remnants in our own galaxy and in the Large and
Small Magellanic Clouds offer opportunities to resolve, measure, and track
expanding stellar ejecta in fine detail, but the handful that are known exhibit
widely different properties that reflect the diversity of their parent
explosions and local circumstellar and interstellar environments. A way of
complementing both supernova and supernova remnant research is to establish
strong empirical links between the two separate stages of stellar explosions.
Here we briefly review recent progress in the development of
supernova---supernova remnant connections, paying special attention to
connections made through the study of "middle-aged" (10-100 yr) supernovae and
young (< 1000 yr) supernova remnants. We highlight how this approach can
uniquely inform several key areas of supernova research, including the origins
of explosive mixing, high-velocity jets, and the formation of dust in the
ejecta.
