The molecular blueprint of life is stored in DNA within the genome. The digital revolution in biology, driven by DNA sequencing, enables scientists to read the genomes of the many microbes and multicellular organisms that populate our world. Today, DNA sequences of over 200,000 microbial genomes are deposited in digital genome databases and have exponentially increased the understanding of how DNA programs living systems. Using this incredible treasure trove of molecular building blocks, bioengineers learn to sequence and synthesize long DNA molecules and to breed useful microbes with the help of computers.