Of course, the obligatory links:

Virtual Libraries | Digital Manuscripts
Resources | Language | Religion | Comics

Virtual Libraries:

• Celtic
  • The Camelot Project: An unbelieveable resource for Middle English Arthurian texts.
  • Carmina Gadelica: This contains the first two volume of the Carmina Gadelica, a landmark collection of prayer-spells from Scotland, many of which are a barely-Christianized version of earlier beliefs.
  • CELT: The Corpus of Electronic Texts: Where you can find all sorts of Irish texts--annals, epics, and so on. Some are translated, others are not.
  • The Celtic Christianity e-Library: containing several texts, such as the imramma and saints' lives.
  • Celtic Twilight: Here you can find Geoffrey of Monmouth's History of the Kings of Britain, Gildas' De Excido, and Sir Gawain and the Green Knight in Middle English.
  • Cornish Language Texts: The most complete collection of classical Cornish texts on the web.
  • Corpus of Gaulish Inscriptions
  • Corpus of Ogham Inscriptions
  • Corpus of Old Welsh Texts
  • Dan Direach: Translations of medieval Irish poetry.
  • The Donegal Fairy Tales: Jeremiah Curtain's classic of Irish fairy tales.
  • Historical Corpus of the Welsh Language 1500-1850: at Cambridge University.
  • The Manx Notebook: A great collection of full texts on Manx folklore.
  • Nemeton: A wonderful, growing collection of medieval Welsh literature. As a bonus, it uses a self-made font that imitates J.G. Evans' typeface for the diplomatic Hergest texts.
  • Ogmios Press: a collection of reprints and facsimilies of early texts, such as the Book of Aneurin, saints' lives, and early Scottish poetry.
  • Oisín i dTír na nÓg: A cute retelling of Oisin in the Land of Youth with pictures by children, in Irish, English, and French.
  • Roman Inscriptions in Britain: a fantastic site, utilizing the out-of-print book of the same name. An important resource.
  • Sengoídelc: Dennis King's collection of Old and Middle Irish quotations--a very interesting site.
  • Tech Sceptra: Erik Stohellou's largely French site, with several Irish texts translated into English with notes by both the original translator and Stohellou.
  • Thesaurus Linguae Hibernicae: University College of Dublin's site, featuring editions and translations of many medieval Irish texts; very similar to CELT.
  • Trecheng Breth Féne: The Triads of Ireland: a collection of triads from Irish manuscripts, made by Kuno Meyer in 1906.
  • The Ulster Cycle The most complete collection I've yet to find. I do a lot of linking to this site.
• Iolo Morganwg
  • The University of Wales Iolo Morganwg Project: detailed project, with letters, essays, details of his works and importance in the history of Welsh literature and Welsh nationalism.
  • The Myvyrian Archaiology: vol. I, II, and III.
  • The Barddas of Iolo Morgannwg: the notorious text of the sixteenth century, which claims to be the wisdom of the Welsh bards, but is mostly Morganwg's laudanum-induced ideas.
  • Barddas Online: images of an entire copy of Barddas.
  • The Iolo Manuscripts: more of Iolo's forgeries, this time courtesy of Google Books.
• Norse
  • Northvegr: The most complete collection of Norse, Germanic, and Old English literature.
  • Norse Saga Home Page: untranslated sagas
  • Netútgáfan: old Norse literature
  • Sagnanetið: images of Norse manuscripts
  • Skaldic Editing Project
• Classical
  • Ancient Greek Texts
  • Année Epigraphique: Selections from the journal of Latin inscriptions
  • Corpus Inscriptionum Latinarum: Portions of the monster-sized CIL; hopefully some day, the whole thing will make it to the web.
  • Corpus Scriptorum Latinorum: texts in Latin.
  • Early Christian Writings
  • Early Jewish Writings
  • Internet Classics Archive
  • Lacus Curtius
  • Perseus Collection of Classical Materials
  • Resource Guide to Norse Mythology
  • Greek Mythology and the Theater
• Medieval
  • Chansons de trouvères: medieval poetry of the French troubadores, untranslated.
  • The Corpus of Medieval English Texts
  • Froissart's Chronicles
  • The Internet Medieval Sourcebook: Containing any number of important texts.
  • In Parentheses: York University's wonderful collection of medieval texts, in PDF format.
  • OMALC: The Online Medieval and Classical Library.
  • The Robin Hood Project: From the same people who brought you the Camelot Project, this site contains the existing Robin Hood ballads from the 13th century onward.
  • The Sir Thomas Malory Society: Has the whole Le Morte d'Arthur in Modern and Middle English.
  • Textes en liberté: many medieval French texts, untranslated.
• General
  • The Avalon Project: Yale's collection of ancient law texts.
  • Sacred Texts: a wonderful site full of just about every sacred text you can think of.
  • RealLiteratureDir.com: collection of biographies on various authors.
• Music
  • Bodleian Library Broadside Ballads: A collection of images of the old broadside ballads.
  • Folk Music of England, Scotland, Ireland, Wales, and America: which is pretty much as it sounds--a comprehensive collection of ballads.
  • Welsh Folksongs

  

• Digital Manuscripts:
  • Collections:
    • The Digital Mirror's Treasures: The National Library of Wales' efforts to put their manuscripts online as digitized images.
    • Early Manuscripts at Oxford University: From the various libraries of the colleges of Oxford, includes the most important Red Book of Hergest (see below). Especially check out the Bodlian Library's collection.
    • Irish Scripts On Screen: includes the Book of Leinster and the Book of the Dun Cow.
    • Codices Electronici Sangallenses: The St. Gall manuscripts: Several of the more interesting manuscripts--mostly Latin, some with Irish glosses--in the St. Gall library, Switzerland. The site is mostly in German.
  • Individual Manuscripts:
    • The Black Book of Basingwerk: a 14th century poetry manuscript.
    • The Black Book of Carmarthen: The great-aunt of Welsh manuscripts.
    • The Book of Aneirin: Puts the whole Book of Aneirin online, following J.G. Evans' fascimile.
    • The Book of Deer: Part of an extensive project regarding the manuscript.
    • The Book of Deer: actual images of the manuscript
    • The Book of Kells: where you can order a digital version of the great manuscript.
    • The Book of Taliesin: Yep, the whole book.
    • Hendregadredd manuscript: an early manuscript of Welsh poetry.
    • The Red Book of Hergest: The granddaddy of Welsh manuscripts.
    • The White Book of Rhydderch: Similar to the RBH in its contents, this shows the section containing the Mabinogi and other romances.
    • The Laws of Hwyll Dda: Contains a good many illustrations, which is unusual in Welsh manuscripts.
    • Beunans Ke: the Cornish play "The Life of St. Ke"
    • Beunans Meriasek: the Cornish play "Life of St. Meriasek"
    • St. Gallen, Stiftsbibliothek, Codex 555: The Vita S. Columbae of Adamnán.
    • The Prose Lancelot: admittedly, this is a French manuscript, but it still applies in my mind.

Resources:

• Academic Links: Nice collection of important links.
• L'Arbre Celtique: (I don't read French very well, but from what I can tell, it has a great collection of texts related to Gaul).
• Celtic Coin Index: provides images and details of coins in Britain.
• School of Celtic Studies: contains articles from Celtica.
• The Decemberists: OK, I just put this here because they have an 18 minute song/ep about the Tain. And they're awesome.
• The Early British Kingdoms Homepage: A good overview of Early and "Dark Ages" Britian. Also, see the Britannia site--I believe they're done by the same person.
• Epona.net: fantasticly detailed site dedicated to studying the Gaulish goddess Epona.
• International Marie de France Society: a nice overview to her works.
• Ireland's History in Maps: a detailed overview.
• Kernunnos.com: site about early Celtic coins and art.
• Medieval source material on the internet: huge collection of links to texts.
• MS-OMIT: short for Manuscript Sources to Old and Middle Irish Tales. This is a great resource (certainly was for me) for finding both the original sources of most (if not all) Irish tales, as well as any translations in existence.
• Nennius' Wonders of Britain: wonderful site studying the Mirabila of the Historia Brittonum.
• The ORB: The On-line Reference Book for Medieval Studies. One of the many good medievalist sites out there.
• Scéla: Similar to MS-OMIT.
• Terry Jones' Barbarians: The Primitive Celts: Jones--yes, that Terry Jones--makes history documentaries now, and this is one of my favorites.
• Vortigern Studies: great site devoted to "Dark Ages" Britain, and in particular to Vortigern.