The standard collection of Latin Christian texts, from the third through the thirteenth century, edited by Migne in 221 volumes. These are not critical editions. http://latina.patristica.net/ http://www.documentacatholicaomnia.eu/a_1010_Conspectus_Omnium_Rerum_Alphabeticus_Littera_A.html
The standard collection of Greek Christian texts, in 161 volumes. Edited in the late 19th century by Migne. These are not critical editions. http://graeca.patristica.net/ http://www.documentacatholicaomnia.eu/a_1010_Conspectus_Omnium_Rerum_Alphabeticus_Littera_A.html
Comprehensive in scope, this encyclopedia includes many entries on both early Christian authors and contemporary German theologians, church historians, and biblical scholars.
A larger project of which the Internet Medieval Sourcebook is a part. While ORB contains comparatively little on early Christianity per se, it does have related materials on Late Antiquity and medieval Christianity.
This little hypertext encyclopedia, while not a work of rigorous scholarship, is a lot of fun and fully searchable. ChurchRodent is a product of the site author’s Church History class project for which he wrote a paragraph on every index entry for Bruce Shelley’s Christian History in Plain Language.
