The resources collected below relate wholly or in very large part to correspondence and – with a few exceptions, mainly in the first section – deal with early modern letters.

Epistolary Centres, Multi-Correspondence Research Projects, and Working Groups

• Archilet: Archivio delle corrispondenze letterarie italiane di età moderna (secoli XVI-XVII)
• Berliner Intellektuelle 1800-1830
• Centre for Editing Lives and Letters (CELL)
• Centro di Ricerca suglio Epistolari del Settecento (CRES)
• Centro di Studi Muratoriani
• Croatiae Auctores Latini: Collectio Electronica (CroALa)
• Circulation of Knowledge and Learned Practices in the Seventeenth-Century Dutch Republic (CKCC)
• Corpora of Early English Correspondence (CEEC)
• Correspondence Corpora: Digitising Experiences of Migration
• Cultures of Knowledge: An Intellectual Geography of the Seventeenth-Century Republic of Letters (Phase I Site, 2009-2012)
• Electronic Enlightenment: Letters and Lives Online (EE)
• Frühneuzeitliche Ärztebriefe des Deutschsprachigen Raums (1500-1700)
• Hijacked Letters
• IMPAcT: From Late Medieval to Early Modern: Thirteenth to Sixteenth Century Islamic Intellectual History
• Letters of Note: Correspondence Deserving of a Wider Audience
• Mapping the Republic of Letters (MRofL)
• Open Correspondence: The Correspondence Network of the Nineteenth-Century Literary World
• The Parsed Corpus of Early English Correspondence
• République des Lettres: UPS 3285 du CNRS
• The Scientific Revolution Homepage: Research Projects (Professor Robert A. Hatch)
• Six Degrees of Francis Bacon: Reassembling the Early Modern Social Network
• Text Encoding Initiative (TEI) SIG: Correspondence
• TORCH Research Network on Enlightenment Correspondences
• Twentieth Century Literary Letters: Digitizing, Visualizing, and Exploring Correspondence Across the Century
• Vernetzte Korresponzenden: Visualisierung von mehrdimensionalen Informationsstrukturen in Briefkorporan
• Voltaire Foundation

Union Catalogues of Letters

• Archilet – reti epistolari: Archivio delle corrispondenze letterarie di età moderna
• Catalogus Epistolarum Neerlandicarum (CEN)
• Corpus Epistolicum Recentioris Aevi (CERA)
• Early Modern Letters Online (EMLO)
• e-manuscripta: The Digital Platform for Manuscript Material from Swiss Libraries and Archives
• Kalliope

Digital Correspondence Editions

• Bess of Hardwick’s Letters: The Complete Correspondence, c.1550–1608
• Correspondance de Pierre Bayle
• The Cullen Project: The Consultation Letters of Dr William Cullen (1710-1790)
• Darwin Correspondence Project
• ePistolarium (CKCC)
• Thomas Gray Archive
• The Correspondence of Hugo Grotius (see also Modelling-Grotius)
• The Correspondence of Constantijn Huygens, 1608–1687
• The Linnaean Correspondence
• The Elizabeth Montagu and the Bluestocking Circle Project
• The Newton Project
• Sir Hans Sloane’s Correspondence Online
• The Spenser Letters

Digital Archives and Catalogues of Correspondence

Individual Institutions

• Biographical Records of the Royal Society
• Håndskriftafdelingens Brevbase, Det Kongelige Bibliotek, Copenhagen
• Index of Literary Correspondence in the Bodleian Library
• Waller’s Manuscript Collection, Uppsala University Library

Individual Correspondents and Correspondence Networks

• Inventory of the Correspondence of Johann Valentin Andreae (1586-1654)
• Francis Bacon Correspondence Project
• Calendar of the Papers of (Hans) William Bentnick
• Correspondence of Théodore de Bèze
• Diplomatic Correspondence of Thomas Bodley, 1585–1597
• The Electronic Capito Project
• Carolus Clusius Project
• Inventory of the Correspondence of D’Alembert
• Corpus of Ioannes Dantiscus’ Texts and Correspondence
• William Dugdale: A Catalogue of his Correspondence
• Les huguenots et le roi: Le combat politique de Philippe Duplessis-Mornay (1572-1600)
• Letters of William Herle
• The Correspondence of Athanasius Kircher
• Medici Archive Project
• Melanchthons Briefwechsel
• The Correspondence of Oswald Myconius (1488-1552)
• The Correspondence of William of Orange, 1549–1584
• The Works and Correspondence of Axel Oxenstierna, Chancellor of Sweden 1612–1654
• Bibliothèque Virtuelle Peiresc
• Thomas Reid Catalogue
• Sloane’s Treasures
• Letters of Philip II, King of Spain, 1592–1597

Hard Copy Correspondence Projects

* also includes an online catalogue

• Edition of the Correspondence (1751-1752) between Luise Dorothea of ​​Saxe-Gotha and Friederike of Mont Martin
• Edition of the Correspondence of Johann Christoph Gottsched
• La Correspondance de Mme de Graffigny
• Projet d’édition de la correspondance d’Hevelius*
• The Correspondence of Daniel Ernst Jablonski (1660-1741)*
• Critical Edition of the Correspondence of Martin Opitz von Boberfeld (1597-1639)
• Leibniz-Edition*
• Monastic Enlightenment and the Benedictine Republic of Letters: The Correspondence of the Brothers Pez
• Josephus Justus Scaliger (1540–1609): Edition of the Correspondence
• Edition of the Letters Philipp Jakob Spener (1635-1705)
• Letters of a Stuart Princess: the Complete Correspondence of Elizabeth Stuart, Queen of Bohemia
• The Ussher Project