Classical Works Knowledge Base (CWKB) – A Cornell database that contains metadata about 5,200 works by 1,500 ancient authors, allowing users with a limited knowledge of the classics’ canonical citation system to simply link to passages of digital texts.
Perseus Project – An evolving digital library of resources for the study of the ancient world that contains thousands of Greek and Latin texts, images, and secondary sources.
PHI Latin Texts – A huge collection of classical and post-classical texts from the Packhard Humanities Institute. Includes a simple and useful concordance utility.
Latin Library – An open access collection of Latin texts: classical, Christian, medieval, and modern.
Corpus Scriptorum Latinorum – A digital library of Latin literature, spanning from the earliest epigraphic remains to the Neo-Latinists of the eighteenth century.
Bibliotheca Augustana – A collection of primary texts in Greek, Latin, and several other languages.
IntraText Digital Library – A collection of primary texts in Latin, including patristics and modern works. Other modern languages are also represented.
Little Sailing – A collection of ancient and modern Greek texts.
Loebolus – Freely downloadable copies of public domain Loeb editions.
Google Books – Indexed by Mischa Hooker, many older, standard editions of classical texts can be found in Google Books.
Classics Index to Online Texts – A large index to primary texts in Greek and Latin and works of classical scholarship that are freely available online.
Corpus Inscriptionum Latinarum (CIL) – Digitized public domain volumes of this comprehensive collection of ancient Latin inscriptions from all corners of the Roman Empire.
Papyri.info – Aggregates and displays information from the Advanced Papyrological Information System (APIS), the Duke Databank of Documentary Papyri (DDbDP), the Heidelberger Gesamtverzeichnis der griechischen Papyrusurkunden Ägyptens (HGV), and Bibliographie Papyrologique (BP), as well as links to Trismegistos.