Bartleby: Great Books Online

Cambridge Collections Online

Christian Classics Ethereal Library

Church Fathers / Patristics (1000′s of online translations)

Harvard Classics/Shelf of Fiction (Quite a bit of philosophy here, as well as public domain fiction)

Hist-Analytic (online history of analytic texts and resources)

Internet Medieval Sourcebook

Islamic Philosophy Online

Jewish Texts Online

Logic Museum Links

Medieval Logic and Philosophy

Medieval Philosophy Online Texts (King)

Perseus (Classic searchable texts)

Project Gutenberg (20,000 etexts)

the Royal Society (online journals stretching back to 1665)