The Internet School of Orthodox Studies Fall 1998 series of 90 minute educational classes are intended to be an examination of the Old Testament prophets, as well as the hymns and prayers of some of the feasts of the Church. This series is presented by Rev. Dr. Frank Marangos.
Established by the Department of Religious Education in 1998, ISOS ran through the Fall of 2005 as a means to assist Orthodox Christians to better understand the teachings of the Orthodox Church. These classes have all been archived on the goarch.org website with the assistance of the Archdiocese Department of Internet Ministries.