EThOS aims to hold a record for all doctoral theses awarded by all UK universities (institutions). There are some gaps which they are gradually filling, but there is a record for at least 90% of all UK theses, some 340,000 records.
EThOS also provides free, direct access to the full text of as many theses as possible (approximately 160,000 at present). It achieves this by harvesting e-theses from Institutional Repositories and by digitising paper based theses as they are ordered by researchers using the system.