Planetary nebulae (PNs) reflect the evolutionary history of their progenitors, they are probes of low- and intermediate-mass stellar populations, and they are the major contributors to carbon and nitrogen recycling in the Universe. Galactic PN studies indicate that their morphology is linked to stellar evolution and chemistry, but the very large uncertainties in the Galactic PN distances, and the selective absorption of PNs in the Galactic disk, hamper the reliability of these results.

The Magellanic Cloud PNs are within reach, and their morphology can be measured with the Hubble Space Telescope, while their distances are known and their reddening not forbidding. They are thus the ideal probes of stellar evolution of low- and intermediate-mass stars, and they are also probes of different metallicity environments.

Our Hubble survey includes ~80 LMC and ~30 SMC PNs, whose morphology, size, energetics, and in some cases central stars properties, UV spectra, and dust properties have been studied. This sample includes about half of all known LMC and SMC PNs. I will present observations and analysis from this survey, and discuss scaling laws between PN parameters, the relation of PN properties to the nature of their progenitor stars, the distributions of PN morphologies in different galaxies, and the PN luminosity function (a commonly-used extra-galactic distance indicator) and its dependence on environmental metallicity.