The LinkedCat+ application makes the 366,000 pages digitised in the homonymous project explorable and searchable in an intuitive user interface. The application is based on the implementation of so-called Open Knowledge Maps, which allows the user to search a corpus of full texts and to visualise the results in thematic clusters. In addition, the application provides the users with a so-called “steam graph” visualization which illustrates the thematic development of an author’s work throughout time. The majority of the articles can be read within the web application as PDF files with full texts underneath. The data set on which the application is based comprises bibliographic entries for approx. 9000 titles, which were recorded in accordance with the RDA rules (Resource Description & Access). Subject indexing was carried out in accordance with RSWK (rules for subject cataloguing) and basic classification, and the authors or persons involved in the treatises were largely linked to the GND (Gemeinsame Normdatei). The full texts were generated using Tesseract and converted into a basic TEI format.