The international moth is an open class. You can build any kind of boat, as long as it abides by the class rules- including being a monohul, 11 feet or less, and no more than 7'4" in beam. The fastest moths, the ones that get all the publicity, are the new hydrofoilers. They are extremely difficult to sail, but can hit speeds of 25 knots in 20 knot winds. However, nonfoiling "lowriders" as they are called, still compete in races, almost always beating the foilers in light air. "fat" classic moths also continue to race, and these are the ones that resemble sunfish. I am currently fixing up a foiling moth, which, unfortunately may replace my sunfish in a couple of seasons.
Below is picture of my pink moth. It needs some work and I may not be able to get it back on the water for another season or so, but I always have my Sunfish!