This poster has been presented at the Music Encoding Conference 2022 at Dalhousie University, Halifax, Canada. It shows the history of MerMEId from its beginning in 2009 until 2022. The “Metadata Editor and Repository for MEI Data” (MerMEId) is a web based tool to capture and enrich data in the MEI header. The tool was originally developed by Axel Teich Geertinger and Sigfrid Lundberg at the “Danish Centre for Music Editing” for their own work on the thematic-bibliographic catalogues of works of Carl Nielsen, Johann Peter Emilius Hartmann, Johann Adolph Scheibe, and Niels W. Gade (Teich Geertinger & Pugin, 2011; Teich Geertinger & Lundberg, 2015). From the beginning—around 2009—the development of the MerMEId was tightly connected to the evolvement of the MEI standard and the editor was presented at numerous occasions. For 2022 the release of MerMEId 2.0 is planned, introducing new features which were implemented in a community effort. Teich Geertinger, A., & Pugin, L. (2011). MEI for bridging the gap between music cataloguing and digital critical edition. In Die Tonkunst, 5 (3), 289–294. Teich Geertinger, A., & Lundberg, S. (2015). MerMEId: Creating Thematic Catalogues Using MEI Metadata. In Roland, P., & Kepper, J. (Eds.), Music Encoding Conference Proceedings 2013 and 2014. Bavarian State Library (BSB), 122–126. URN: http://nbn-resolving.de/urn:nbn:de:bvb:12-babs2-0000007812.