In this interview, NYU Law Professor Christopher Sprigman discusses his experience conceiving, drafting and producing the Indigo Book, a manual of legal citation that replicates the uniform system of citation expressed by Harvard Law Review’s Bluebook. Formerly known as “Baby Blue,” the Indigo Book is published by Public.Resource.Org under a creative commons license and may be freely modified or distributed without restriction under copyright law. Professor Sprigman details his vision for the Indigo Book, the legal copyright and trademark uncertainties the project faced, and his plans for the citation manual’s future.