Computers are used all over the world in a variety of contexts by users with all levels of technical experience. This includes users such as kindergarteners, older users, people with various impairments, people who are busy doing other tasks (such as driving a car), and users with differing levels of education, literacy, and socio-economic means. The concept of computer interfaces that will be easy to use, for all of these users, in all of these different situations, is known as universal usability. Making progress towards this goal requires innovations in techniques for gathering and understanding requirements; designing and developing interfaces; evaluation and assessment; standards practices; and public policy, and much work in this field remains to be done. This survey presents an overview of universal usability as it currently exists in the human-computer interaction literature, and presents some future directions for work in universal usability.