Digital organisms evolving freely by natural selection do no ``useful'' work. Natural evolution tends to the selfish needs of perpetuating the genes. We can not expect digital organisms evolving in this way to perform useful work for us, such as guiding robots or interpreting human languages. In order to generate digital organisms that function as useful software, we must guide their evolution through artificial selection, just as humans breed dogs, cattle and rice. Some experiments have already been done with using artificial selection to guide the evolution of digital organisms for the performance of ``useful'' tasks [1,89,91]. I envision two approaches to the management of digital evolution: digital husbandry, and digital genetic engineering.