A man goes into a pet shop to buy a parrot. The shop owner points to three identical looking parrots on a perch and says: “The parrot on the left costs $500”. “Why does the parrot cost so much?” Asks the man. The owner says, “Well the parrot knows how to use a computer”. The man then asks about the next parrot, to be told that this one costs $1,000 because it can do everything the other parrot can do plus it knows how to use the UNIX operating system. Naturally, the increasingly startled man asks about the third parrot to be told ...