PRONOM is a web-based technical registry to support digital preservation services, developed by The National Archives of the United Kingdom. PRONOM was the first and remains, to date, the only operational public file format registry in the world, although the "Magic File" repository of the File Command has served this role in a less formal capacity for two decades. Other projects to develop technical registries, including the UK Digital Curation Centre's Representation Information Registry, and the Global Digital Format Registry project at Harvard University, are now in progress.