The Dissemin sevice uses Annif. Through the Dissem.in web page researchers and authors of scientific papers can check whether or not their publication is open access. Dissemin can also suggest open access platforms for the publication. It also helps in the upload process: here it offers the user suggestions that Annif gives based on the HAL classification to work with. Also take a look at this describing the use of Annif in an interesting research project
Annif has been tested and used with quite some interest both in Finland and abroad. It has been involved in for example an interesting Dutch research project called Entangled Histories that focuses on early modern ordinances (law texts), take a look at this blog post to find out more! The the Research department of the National Library of the Netherlands has also used Annif as a part of their own larger tool1 for automated indexing, see this documentation. Also, feel free to join the email list / Google group annif-users - a forum for the groving number of people and organizations interested in Annif and automatic subject indexing!
1Haighton, T. and Veldhoen, S., (2021) Assisted keyword assignment using Annif. KB Lab: The Hague. http://kbresearch.nl/annif/.