“Gordius, the King of Phrygia, once tied a knot that no one could untie. It was said that he who solved the riddle of the Gordian Knot would rule all of Asia. So along comes Alexander the Great, who chops the knot to bits with his sword. Just a little different interpretation of the requirements, that’s all… and he did end up ruling most of Asia.” So begins chapter seven of one of my favourite programming books of all time.