This list is intentionally selective. A summa summarum of sorts, it is not meant to replace existing directories of online classics resources, but rather point to them.
Ad Fontes Academy
The Latin Library
Links to the texts of Apuleius, Augustus, Caesar, Cato, Catullus, Cicero, Ennius, Horace, Juvenal, Livy, Lucan, Lucretius, Martial, Nepos, Ovid, Persius, Plautus, Propertius, Quintilian, Sallust, Seneca, Suetonius, Tacitus, Terence, Tibullus, Vergil, as well as miscellaneous Christian, medieval, and neo-Latin authors.
The Perseus Project
A continually growing digital library of resources for studying the ancient world. Ancient texts and translations, philological tools, maps, extensively illustrated art catalogs, and secondary essays on topics like vase painting. Information on ancient history and science, the Roman world, archaeology, and geography.
Internet Ancient History Sourcebook
Emphasizes access to primary sources for use in classroom situations. Navigation is simple and pages load fast (few graphics). Includes links to visual and audio materials, metasites. A model of efficiency and utility.
Dana F. Sutton
The Philological Museum: An Analytic Bibliography of On-Line Neo-Latin Texts
Latin texts, written during the Renaissance and later that are freely available to the general public on the Web (texts posted in access-restricted sites, and Web sites offering electronic texts and digitized photographic reproductions for sale, are not included). As of 20 January 2011, there were 37,300 records.
Maria C. Pantelia
Electronic Resources for Classicists
Links to classical resources, texts, databases, web projects, e-publications, publishers and journals, bibliographies and bibliographical indices, images, course materials (college as well as K-12), author-specific sites, fonts and software, professional organizations, online seminars, and classics department home pages.
Voice of the Shuttle
A monster directory of online humanities resources. The classical studies page includes links to general classics resources, language resources, archaeology & art (on archaeology page), history & culture, literature, mythology, philosophy, journals, listservs & newsgroups, classics depts., programs & associations, course syllabi, conferences, and calls for papers. Also a good place to start if you are looking for online information on general humanities resources, anthropology, archaeology, architecture, area & regional studies, art & art history, cultural studies, cyberculture, history, legal studies, linguistics, literature, literary theory, media studies, minority studies, music & dance, philosophy, photography, politics & government, postindustrial business theory, religious studies, science, technology, & culture, technology of writing, or women's & gender studies.