Carrie - Full-text electronic library hosted by the University of Kansas.
Cornell Electronic Text Center - Not an online text archive but more an informational resource on the subject of electronic texts; includes information on and links to electronic texts, including various online archives both large and small, more general and more specific.
Corpus of Middle English Prose and Verse Bibliography - An extensive archive of Middle-English electronic texts (none of which are translated into modern English, however), including works by Chaucer and the ubiquitous Anonymous.
Digital Library Project - A University of Pennsylvania selection of digital library collections, exhibits, and finding aids prepared by digital librarians. Includes a section on obscure texts by women writers.
Duke Papyrus Archive - Features online access to over 1,375 ancient Egyptian papyri at Duke University.
New Zealand Electronic Text Centre (NZETC) - Hosted by Victoria University of Wellington. John Cawte Beaglehole Letters, Modern New Zealand Texts Collection, Print History Project and the New Zealand literary journal Sport.
Oxford Text Archive - 2,500 texts, corpora, and reference works. Some are freely available.