Sources

Al-Tafsir 

Quran, tafsirs (commentaries), and Quranic Science texts accessible online, both in the original Arabic and in translations. It is the first website to cover all seven schools of Islamic law (madhhabs). The accuracy and authenticity of the texts is ensured by a rigorous validation process, and it is safeguarded against future alterations by high security mechanisms.

The Alpha 

Coptic Orthodox Electronic Publishing Australia. Their numerous resources include downloadable recordings of Coptic liturgies in the Coptic language.

Arunachala & Bhagavan Sri Ramana Maharshi 

A non-profit website created for the benefit of those who are seriously interested in Advaita and the paths to Self-realisation. With downloadable materials and links to other sites relating to Indian scriptures.

The Buddhist Archives of Dr Alexander Berzin 

These archives present material from all five Tibetan traditions: Nyingma, Sakya, Kagyu, Gelug, and Bon, as well as comparisons with Theravada Buddhism and Islam. Also featured are Tibetan astrology and medicine, Shambhala, and Buddhist history.

The Collected Works of Shinran

Translations and original Japanese texts of the founder of the Pure Land (Jodo Shinshu) school of Buddhism, with introductions, glossaries, and reading aids by an international team of devoted students. Sponsored by the White Lotus Center for Shin Buddhism/Myoko-in Temple.

Documenta Catholica Omnia 

Omnium Paparum, Conciliorum, Ss Patrum, Doctorum Scriptorumque Ecclesiae qui ab Aevo Apostolico ad usque Benedicti XVI Tempora Floruerunt, i.e. the works of all the Popes, Councils, Holy Fathers, Doctors and Writers of the Church who have flourished from the age of the Apostles down to the times of Benedict XVI, downloadable for free in their original languages.

Ghazali Website

This virtual online library provides the complete works of al-Ghazali in the original language—that have been published in print—and in translation. Additionally primary research material, including hundreds of full length books and articles are available gratis in communem delectationem.Originally, this was a part of the remarkable Islamic Philosophy Onlinewebsite.

GRETIL, Indian Texts

Göttingen Register of Electronic Texts in Indian Languages and related Indological materials from Central and Southeast Asia. A “cumulative register of the numerous download sites for electronic texts in Indian languages.” GRETIL registers only e-texts that are freely available for scholarly purposes and can be employed for word search etc. in a standard word processing programme. One of the most important online resources for Indology and related disciplines, including all major Vedic texts, often in more than one revised version.

IHSAN Network—The International Hadith Study Association Network

Part of the Thesaurus Islamicus Foundation‘s Sunna Project, the Hadith Database allows for the full text of the Foundation’s printed editions of hadith collections to be searched according to various criteria in their original Arabic. Requires free registration.
The Sunna Project has become synonymous with definitive critical hadith editions, and their volumes are now a de facto reference standard for both traditional Islamic and modern scholars.

Internet Sacred Text Archive 

“A quiet place in cyberspace devoted to religious tolerance and scholarship.”
This vast open library is the largest such repository on the Web, including all the foundational texts in their original languages and usually providing various translations and commentaries. Variable quality.

Jewish Encyclopedia

The unedited full-text of the 1906 Jewish Encyclopedia, containing over 15,000 articles and illustrations. It does not cover a significant portion of contemporary Jewish History (e.g., the creation of Israel, the Holocaust, etc.), but it contains a wealth of information that is remarkably relevant today.

Lapis Lazuli Texts

“An original effort aiming to translate a selection of important texts from the Chinese Buddhist canon into English, for the express purpose of universal free distribution.” A remarkably sober page, with a wealth of rare and high-quality texts.

Mahabharata Resources 

The purpose of this site is to provide resources on the Great Itihasa, Mahabharata: “what is not found here is to be found nowhere.”

Mechon Mamre

The Mamre Institute, run by Jewish scholars based in Jerusalem, contains the Hebrew Bible (Tana”kh) and the RaMBaM’s Complete Restatement of the Oral Law (Mishneh Torah). Lots of resources in Hebrew and English.

OrthodoxWiki 

A free-content encyclopedia and information centre for Orthodox Christianity. This a sort of Wikipedia of things Orthodox, including images, with contents in several languages.

Prometheus Trust 

With the lucid teachings of Plato abiding firmly at its centre, the path of living philosophy or love of wisdom provides the stable foundation for the work of The Prometheus Trust, including their very comprehensive range of translations of Plato himself, Aristotle, Proclus and other ancient philosophers.

Sefaria

“The People of the Book”, Sefaria is a non-profit organization dedicated to further Jewish learning in an open and participatory way, assembling a free living library of Jewish texts and their interconnections, in Hebrew and in translation. All contents are easy to navigate, hyperlinked, downloadable and sourced. Highly recommended.

Sefarim: Hebrew Bible with commentary 

A site in French and Hebrew, featuring the Tanakh, Masoretic Text or Hebrew Bible, with Rashi’s commentary. Here is a similar site in English, but Rashi’s text is only in Hebrew.

Wengu Zhixin 

“Reviewing the old, acquiring the new”, after the confucian saying, this excellent site allows you to read Chinese classic texts in original language and with some translations. Your browser must be enabled to display Chinese, but you can also visit this site in No-Chinese mode.