The Basic Register of Thesauri, Ontologies & Classifications (BARTOC) is the largest online directory of Knowledge Organization Systems (KOS). It provides free access to the metadata of more than 3,000 terminologies in 20 different languages. BARTOC unifies different vocabulary services on a single platform and enhances the visibility of the existing KOS in various domains. The initiative was founded and developed by Andreas Ledl at the Basel University Library, Switzerland in 2013. In 2020 the Register was moved to and is being hosted by the head office of the common library network, VZG in Göttingen under a new technical infrastructure developed within the framework of the project coli-conc. This presentation will give an overview of the BARTOC project, its history and will provide an update on its services, especially with regard to the project coli-conc and elucidate the latest technology implemented by the VZG.