OPACs: an overview: Historical perspective

Having been around in one form or another for some years, decades almost, the term OPAC and the corresponding concept will be familiar to most librarians/information workers. The earliest OPACs can probably be ascribed to the first true online circulation systems, heralded by the arrival of Geac in the United Kingdom around 1980. Prior to that time the quantity of bibliographic information held for the purposes of circulation control ranged from inadequate to non‐existent.