Chant data archives  
CANTUS - a database for latin ecclesiastical chant Department of Early Music at Budapest
CANTUS PLANUS AUSTRIA (Web Archive for Medieval Music in Austria) Late Medieval Liturgical Offices LMLO
Giacomo Baroffio - Iter Liturgicum Italicum Monumenta Musicae Byzantinae at Copenhagen
Analecta Hymnica La Trobe University Medieval Music Database
Christian Meyer (Nancy): Outils pour l’analyse et la description des manuscrits liturgiques notés
Cantus Index  
Printed liturgical sources  
Renaissance Liturgical Imprints (RELICS)  
Chant theory databases  
Thesaurus Musicarum Latinarum (TML) at Indiana Lexicon Musicum Latinum at Munich (de, fr)
Chant homepage  
The Gregorian Chant Home Page at Princeton International Association for Studies of Gregorian Chant (AISCGre)
Musicologie Médiévale
Institute of Medieval Music, Canada Abbaye Saint-Pierre de Solesmes
Libraries, catalogues, manuscripts  
RISM Libraries Directory Manuscritpa Mediaevalia
Bayerische Staatsbibliothek München British Library London
CEEC - Codices Electronici Ecclesiae Coloniensis Danish Liturgical Fragments from the Middle Ages edited by Knud Ottosen
Hill Monastic Manuscript Library Codices Electronici Sangallenses (CESG)
e-codices (Virtual Manuscript Library Switzerland) Österreichische Nationalbibliothek Wien
Biblioteca Apostolica Vaticana Gregofacsimil
Musicology homepage  
Royal Holloway Music Dept's Golden Pages The International Musicological Society (IMS)
Related research areas  
Einbanddatenbank Wasserzeichenkartei Piccard
Zeitrechnung des Deutschen Mittelalters und der Neuzeit von Hermann Grotefend ORBIS LATINUS
Historical Auxiliary Sciences (Codicology)
Klöster in Bayern Acta Sanctorum Database
Ökumenisches Heiligenlexikon Documenta Catholica Omnia