From the Hero Games website:
Hero Designer is special software for creating HERO System characters. Programmed specifically for creating HERO System characters, it's an invaluable time-saver for many Hero gamers, particularly those of you who like to tinker with character designs or quickly see what happens if you change something on your character's sheet.
In addition to Hero Designer itself, we also sell Character Packs featuring characters, vehicles, weapons, gadgets, spells, powers, and other material from our books in Hero Designer format. We do all the work so you don't have to! It's the perfect way for a GM to prepare villains for his latest adventure or a player to see how a power from one of our books works with his character.