Bibliotheca Augustana:Index of Latin literature. Navigation is in Latin: you can browse alphabetically or by century. Also includes German, English, and Greek literature.
Perseus Project Latin Texts:With accompanying English translations and links to dictionaries, commentaries, grammars, and other tools.
A Private Library - James O'Donnell: The classification system in this library is not very intuitive, but if you dig, there are Latin, Neo-Latin, German, and English texts here.
Bibliotheca Latina: From the University of Wisconsin. Extensive list of links to Latin texts (classical, medieval, and neo-Latin). Page is entirely in Latin.
Center for Electronic Texts in the Humanities: A compendium of Latin texts.
CNP's Online Catalog - Music with Latin Texts: Lists a collection of Latin texts written to music. The texts themselves are not available online but must be ordered.
Corpus Scriptorum Latinorum: Online texts from Augustine to Vergil, sorted by author and including links to Latin, English, and foreign language translations.
Electronic Text Center Latin Resources: A good sized collection of Latin texts. Unfortunately, all but Boethius' Consolatio Philosophiae and Ovid's Metamorphoses are restricted to use by students at the University of Virginia.
Labyrinth Latin Library: A collection of ancient and medieval Latin texts.
LacusCurtius: Latin Texts: The main index page for the Latin texts on LacusCurtius: Pliny's Natural History, Frontinus, Vitruvius, Ptolemy's Geography.
Latin Texts - Orbis Latinus: Latin texts from 240 BC to present, organized by period.
Latin Texts at CELT: CELT is a resource for contemporary and historical Irish documents in literature, history and politics. This particular link takes you to their collection of Latin texts.
Latin Vulgate: A site for helping to Learn Latin, using the Latin Vulgate as reading material. English + Latin side-by-side.
Lupa: Helps for searching for classical texts. Navigation is in Latin.
Nordic Neo-Latin Literature: A searchable database of Neo-Latin (1530-1800) literature from Nordic countries.
Project Libellus: Free Latin and Greek texts with certain redistribution restrictions.
The Later Latin Society: Latin, classical, medieval and modern; texts, symposia, grammatical aids, Attic Nights of Aulus Gellius, Res Gestae of Augustus Divus, Erasmus, and Philobiblon of Richard de Bury in Latin
The Latin Library: A collection of Latin texts: classical, Christian, medieval, and modern, including such classics as Lewis Carroll's "Gabrobocchia".
The Library: A library of Latin works, with introductions and translations (Dana Sutton, U of California).
Thesaurus Precum Latinarum - Treasury of Latin Prayers: Latin prayers with English translations. Includes a guide to pronunciation of Ecclesiastical Latin.