Carbon compounds of different shapes and sizes build up all life on earth, but they can also be produced artificially. This is called organic synthesis and is central in chemistry. Here molecules are tailored and built in the service of mankind. The most tempting thing is perhaps to produce materials with entirely new properties, or effective medicines with fewer side effects. This year’s Nobel Prize Laureates in chemistry have developed a new type of reaction with broad areas of application in organic synthesis. The reaction is termed metathesis.