Although the digitisation of library collections is a complex challenge that only began in the 21st century, it is based on centuries of systematic collecting, storing and cataloguing. It was the Dutch scholar and first official imperial librarian Hugo Blotius who, in the 16th century, initiated the cataloguing of holdings by author and subject in the form of book catalogues, while Gottfried van Swieten began in 1780 to record the collections of the Imperial Court Library on slips of paper – thus inventing the innovative system of the flexibly expandable card catalogue, which continued to be used in typewritten form until the introduction of digital cataloguing in online databases in 1995.

All the previous technical developments are reflected in the organisation of digitisation, which is only possible if everything has been systematically recorded first: a multi-stage process based on identifiers such as barcodes and signatures includes the visual inspection of the books, the recording in the catalogue system, restoration work and the integration of the newly created digitised material into the library system.

For this, the works selected must firstly comply with the legal framework of copyright protection and, secondly, must be of a format and conservation condition that allows them to be digitised. Google can be supplied with the necessary metadata with the help of the improved bibliographic descriptions in the Austrian National Library catalogue. A complex logistical workflow has to be implemented, from retrieving the selected works from the various collections and stacks to transporting them for digitisation.

The digital copies of the ABO project can be searched via the QuickSearch library catalogue and the ÖNB Digital portal. Thanks to the public-private partnership with Google, large quantities of printed works have not only been digitised but also provided with full text. They are thus available to the digital humanities and social sciences as a data corpus for non-commercial use (copyright notice: ‘No Copyright - Non-Commercial Use Only’) and can also be used as training data for machine learning.

Valuable holdings such as those of the State Hall are thus made available to the general public as well as to researchers. The ABO project and other Austrian National Library digitisation projects contribute to the preservation, availability and visualisation of the cultural heritage on various platforms such as Kulturpool and Europeana.