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.