Online resource includes digitized content of around 3,000 entries from the print edition published under the direction of Richard Goulet from 1989 to 2018. It is the collaborative effort of 231 scholars and researchers from twenty countries and includes biographical and bibliographical information for Greek or Roman pre-Socratic philosophers from the sixth century B.C. through the Neoplatonist philosophers near the end of the sixth century A.D. It also includes important witnesses to the philosophical tradition in antiquity and certain Byzantine scholars whose role was important for the conservation and transmission of Greek philosophical heritage.