The Principles of Universal Design were developed in the 1980s at North Carolina State University to make environments accessible to all people regardless of ability. These principles were later extended to education as Universal Design for Learning (UDL) which calls for presenting curriculum in flexible ways to meet diverse learner needs. UDL is based on three principles: providing multiple means of representation, action and expression, and engagement. When applied to curriculum development, UDL helps create materials that are accessible to all learners through varied instructional methods and assessment options. Assistive technologies can support UDL implementation but are not required as the goal is flexible designs that meet individual student needs.