If you are interested in the story of Deirdìre, or Irish myths in general, you might like the following links:
- Corpus of Electronic Texts version of Deirdìre (University College Cork)
- The Cattle-Raid of Cooley (Táin Bó Cúalnge) is the central epic of the Ulster cycle. This HTML edition pairs an adaptation of the English translation of Joseph Dunn (1914) with the Irish transcription of Ernst Windisch (1905.)
- High-quality digital images of Irish manuscripts, including the Book of Leinster.
- An excellent list of public-domain Irish mythological texts (with English translations).
Many more could be appended -- feel free to suggest other links.