Supernova remnants (SNRs) are the primary source of energy within the interstellar medium (ISM). The million-degree gas in SNR interiors is the dominant contributor to the "hot phase" of the ISM; the details of SNR expansion and evolution determine how this hot gas is distributed on large scales. The Large Magellanic Cloud (LMC) provides a large sample (~ 40) of SNRs in various environments, at a known distance (50 kpc) and with little internal obscuration. The Small Magellanic Cloud (SMC) provides another such sample (~ 20), again at a known distance (60 kpc). SNRs in the MCs are observable with reasonable resolution and sensitivity, without Galactic uncertainties in distance and intervening absorption. This makes these remnants ideal for population studies.