Internationally, the structures of contemporary university adult and continuing education (ACE) reflect the higher education traditions from which they spring. With the increasing policy focus on lifelong learning over the last decade, some countries are reaching a stage where adult learners now represent a majority of students in higher education. A distinctive form of university ACE lies in the extramural tradition, with specialist centers or departments dedicated to providing university courses to adult learners. Current debates focus on the merits, or otherwise, of mainstreaming versus dedicated provision for adult learners. How this balance tips is influenced by broad social and economic factors, mediated through university strategies at particular times.