Album interactif de paléographie médiévale
http://paleographie.huma-num.fr/
Antiphonale Synopticum
http://gregorianik.uni-regensburg.de/info
Archive of Iberian Polyphony
https://iberianpolyphony.fcsh.unl.pt
Biblioteca Digital Hispánica
http://www.bne.es/es/Catalogos/BibliotecaDigitalHispanica/Inicio/index.html
Books of Hispanic Polyphony
https://hispanicpolyphony.eu/
Cantigas Medievais Galego-Portuguesas
http://cantigas.fcsh.unl.pt/
Cantus Index for Office and Mass
http://cantusindex.org
Cantus planus Regensburg
http://www.uni-regensburg.de/Fakultaeten/phil_Fak_I/Musikwissenschaft/cantus/
Cantus Ultimus
https://cantus.simssa.ca/
Catalog of the House of Braganza's Museum-Library Musical Archive
https://vvpducalmus.fcsh.unl.pt/
CMN - Catalogue des manuscrits notés
https://www.musmed.fr/CMN/CMN.htm
Center for the History of Music Theory and Literature
https://chmtl.indiana.edu/
DIAMM - Digital Image Archive of Medieval Music
http://www.diamm.ac.uk/
Differentiae Database
https://differentiaedatabase.ca/
Digital Resources for Early Music
https://sites.google.com/a/haverford.edu/digital-resources/
Digital Tools for Manuscript Studies
https://digitaltoolsmss.library.utoronto.ca/
e-codices - Virtual Manuscript Library of Switzerland
http://www.e-codices.unifr.ch
Gallica - Bibliothèque numérique
http://gallica.bnf.fr
Grotefend - Zeitrechnung des Deutschen Mittelalters und der Neuzeit
http://bilder.manuscripta-mediaevalia.de/gaeste//grotefend/grotefend.htm
IDEM - Integrated Database for Early Music
http://idemdatabase.org/
Monophonic Chansons in Polyphonic Textures (c. 1450-1550)
http://chansonmelodies.sbg.ac.at/db/intro.php
Musicologie Médiévale - Resources for Medieval Musicology and Liturgy
http://gregorian-chant.ning.com/
MMMO Database - Medieval Music Manuscripts Online Database
https://musmed.eu/
Oxford Cantigas de Santa Maria Database
http://csm.mml.ox.ac.uk/
PhiloBiblon
https://bancroft.berkeley.edu/philobiblon/
Renaissance Liturgical Imprints: A Census (RELICS)
http://quod.lib.umich.edu/r/relics/
Spanish Early Music Manuscripts Database
http://musicahispanica.eu
The Catalogue of the Monastery of Arouca
https://arouca.fcsh.unl.pt/
The CMME Project: Computerized Mensural Music Editing
http://www.cmme.org
The Lugo Codex
https://scholarworks.iu.edu/dspace/handle/2022/17230
Usuarium - A Digital Library and Database for the Study of Latin Liturgical History
https://usuarium.elte.hu/calendarlabels