DIAUMA is an online database with TIFF files of around 800 language and dialect maps created between 1924 and 1956 - mainly relating to the German-speaking area, but also to countries that no longer exist in the form depicted, such as Czechoslovakia and Yugoslavia or south-eastern European countries such as Romania.
Among other things, maps from the unpublished "Dialektatlas Österreichs und seiner Nachbarländer" (DAÖ) and those created in the context of the "Bavarian-Austrian Dictionary" - later the "Dictionary of Bavarian Dialects in Austria" (WBÖ) - are included and partially georeferenced. DIAUMA also contains examples of decidedly persuasive cartography with an explicit (linguistic) political orientation.
The metadata on the maps provide information on the author, title, content, size/scale, time of creation and other details with the aim of supporting the (scientific) historical contextualization of the map material. The online search can be filtered according to "persons" (e.g. authors) and "references" (thematic or archival aspects).