H2O Open Casebook: law textbooks that cost nothing and can be remixed

H2O is a free platform for creating and sharing open-licensed law casebooks, built by the Library Innovation Lab at the Harvard Law School Library. It began at the Berkman Klein Center. The reasoning is simple: most of a casebook is public-domain court opinions, yet students pay thousands of dollars for them, so H2O lets a professor assemble, edit and share a casebook online for free. By default, materials are licensed for sharing and remixing for non-commercial uses with attribution. It is aimed at teachers, but a student or self-learner can borrow any published casebook. The directory also points to other free casebooks, such as one on copyright law.

Citation: 'H2O Open Casebook' (Library Innovation Lab, Harvard Law School Library) https://lil.law.harvard.edu/our-work/h2o/; 'The H2O Casebook Directory' (H2O) https://about.opencasebook.org/blog/2020/04/28/the-h2o-casebook-directory/ both accessed 18 October 2026.