This is a new branch of science which combines biology and genetic engineering to create completely new artificial products, as opposed to genetic engineering which just tinkers with existing natural systems. Applications include biological computers, the synthesis of biological molecules for medical applications, and various industrial uses. It seems the practitioners often prefer to think of themselves as engineers rather than biologists. For the humble lexicographer, this poses the question of whether we need to extend our definitions of biology and biologist to cover the study of both natural and articifical systems. Heavens above, worlds are colliding!