Progeny is the darkest and most obscure of all vampire systems.
Progeny is a vampire system, where registered players (vampires) are wearing special devices (mainly a HUD). They feed on humans. They permanently need to feed in order to stay alive. Nobody can join the game unless offered from one of the members.
Players inside Progeny form a heretical structure “family tree”, and a social structure “clans and houses”. The development team are known as Diabolics lead by Lachiel “the source”, there are currently 12 arch vampires each the progenitor of a Blood Line “subspecies of vampires”. Each new player is a descendant “Progeny” of one of the arch vampires.
Players assume the role of a Vampire in SL and can participate in a House, or get involved in Clan politics. Some choose to become outcasts and exist outside of traditional vampire society.
Basically if you don't want to sink all your money into bloodlines, or are tired of the "money pit" that it is. This is a much better, and cheaper (The system is free) - system for you. Bloodlines players will put Progeny Vampires down, because they know they are a real threat to their money scheme.
The legend ( backstory ) says that Lachiel, the founder of Progeny Vampire Systems, is a devil. That maybe he fought for Lucifer in the First Angelic War, then he was found in hell, convinced that Better to reign in Hell than serve in Heaven . All the roleplay among Progeny is strongly related with veneration of the devil.
Since there is no other way to enter Progeny except for being invited, no SLGI member has worn the vampire system. However, since on their main site there is a list of online players, based on the length of that list, we speculate that there must be about 3000 registered players. Among the online grid population, Progeny vampires should be less then 0.1%.