Livebearers have been a steady favorite in the aquarium hobby for some time now, and why not? After all, they add extremely colorful variety to your tanks, and are fairly easy to breed.
They're called livebearers because fertilization and development of the eggs occur internally in the female, thus the fry are born free-swimming. These broods can occur about once a month, and sometimes re-mating isn't necessary for multiple broods.
All livebearers (which include Guppies, Platies, and Mollies) require well-planted tanks with a varied diet of vegetable matter in their feedings.