This Java OpenStreetMap Editor (JOSM) plugin automatically assigns addresses to an object. It uses the BEV Address Data Reverse Geocoder for this. That web service uses the address data sets released by the Bundesamt für Eich- und Vermessungswesen (BEV) in Austria.
To use it, simply activate the austriaaddresshelper plugin in the JOSM preferences dialog. In order to assign an
address to an object in Austria, press Ctrl + Shift + A (Linux, Windows) / ⌘ + ⇧ + A (macOS) or simply use the
"Fetch Address" menu item from the "Tools" menu.
The data source is the address data set of the Austrian Federal Office for Calibration and Measurement (Bundesamt für Eich- und Vermessungswesen) (see section "Unentgeltliche Produkte").
Data: © Österreichisches Adressregister 2017, N 23806/2017
There is also a written permission for the OpenStreetMap project to use the data.