For decades, biologists have relied on written descriptions of protocols to guide their experiments in the laboratory. However, due to recent technology trends, the practice of describing protocols with free-flowing English-language text is quickly becoming inadequate and obsolete. First, we are witnessing immense advances in laboratory automation systems. Microfluidic chips have been evolving at a pace faster thanMoore’s Law, with the number of valves per chip doubling every four months . In order to leverage such technologies for biological experimentation, it will be necessary to express the protocols in a format that is not only comprehensible by humans, but also by machines. Second, the complexity of biology protocols is increasing dramatically. As we attempt to synthesize living systems as a composition of many parts, we will need to execute lengthy protocols with great precision. This will require a standard language for unambiguously describing the steps needed to synthesize a part, as well as for composing parts into a larger system.