OER are "…teaching, learning, and research resources that reside in the public domain or have been released under an intellectual property license that allows for free use, reuse, modification, and sharing with others, including full courses, course materials, modules, textbooks, streaming videos, tests, software, and any other tools, materials, or techniques used to support access to knowledge.” (Texas Senate Bill 810 2017 and TEC 51.542). OER textbooks, like those from OpenStax and Open Textbook Library, are free for students with no associated fees and have a Creative Commons or a Public Domain license."