It is named after Ivan Petrovich Pavlov, the guy who demonstrated conditional responses to stimuli in dogs. I would have called the language "Pavlov", but it seems all the cool names for languages have already been used by someone else.
Provide an operating system and computer language that can learn and improve its performance in a natural manner. Adapt to user feedback in an intelligent manner.
Petrovich provides two methods of influencing its behaviour: rewards and punishments. Whenever Petrovich does something the user doesn't approve of, the user can punish it. Conversely, whenever Petrovich does something useful, the user can reward it.
Petrovich then adapts its behaviour to avoid punishment and enjoy more rewards.