Includes some apocryphal books.

The books have annotations.

This contains additional patristic writings not included in the original 38-volume set.

This includes the writings of other saints besides the Fathers. It includes texts in Latin and other languages not yet available in English translation.

St. Augustine of Hippo

One of the Fathers of the Church

A painting by Maarten de Vos, 1570

Image source link:

Q & A

1. Can you give an example of how to find a book from the "Documenta Catholica Omnia" (DCO) website?

RESPONSE: Sure. Suppose you want to find a book, Commentary on Isaiah the Prophet, by St. Jerome. When you click the DCO link above, the homepage of the DCO will open. Find the list of Alphabets near the header. This is the index of Authors in Alphabetical order. However, you need to look for the author in their Latin names, because the website is in Latin. This means that you cannot find St. Jerome's book using the J index. If you don't know the Latin equivalent of "Saint Jerome," use the Google Language translator to help you. (The Google Language translator is also in website. You will find it in the "References & Tools" menu under the Resources tab.) At the Google Language translator, set the left box to English, and the right box to Latin. Now, type "Saint Jerome" in the left box. The right box will display "Sancti Hieronymi." This tells you that you have to click the "H" index tab and start looking for Hieronymus there. So, go back to the DCO homepage and click the H index. Then look for "Hieronymus" under the "Auctor" label, and the title of the book under the "Operis Titulus" label. In the list of books you will find "Commentariorum in Isaiam Prophetam Libri Duodeviginti," which is the book that you are looking for. (Knowing a little Latin helps). This title is a link to the book. Before you click the link, look at the far right, which says "pdf." This means that the book is downloadable in pdf format. If it says "doc," then you know the document is in Microsoft word format. Now, in the next column to the left of the format column is a language code. If it says "EN," then the book is available in English translation even if the title is given in Latin. If it says "MLT," then the text is in Latin, from the original Migne's Latin text. If you want to download the text, then click the title.