The past three decades have witnessed steady growth in our ability to harness DNA branched junctions as building blocks for programmable self-assembly of diverse supramolecular architectures. The DNA-origami method, which exploits the availability of long DNA sequences to template sophisticated nanostructures, has played a major role in extending this trend through the past few years. Today, two-dimensional and three-dimensional custom-shaped nanostructures comparable in mass to a small virus can be designed, assembled, and characterized with a prototyping cycle on the order of a couple of weeks.