The IAPSOP is an American non-profit organization dedicated to digitize and thus preserve Spiritualist and occultist periodicals published before the Second World War. It has a rich and growing archive of such publications, shared under a Creative Commons license that permits free non-commercial use. It is an extraordinary resource for historians of occultist and spiritualist milieus.

FOTA (The Friends of Theosophical Archives) is an organization that promotes knowledge of, and support for, Theosophical archives across the world. For this purpose, “Theosophy” is defined in the same way as in the editorial pages of Theosophical History, and is not restricted to any one tradition or country.

The Hermetic Library was started in 1996 and is thus probably the oldest repository of esoteric texts online. It was established and run by practitioners of a primarily Thelemic bent, and its collection obviously reflects this. It is a useful resource for certain strands of twentieth century and contemporary esotericism, from recent developments in ritual magic and the Thelemic scene in particular, to the ontological anarchy of Hakim Bay.

The IGPP in Freiburg not only holds an outstanding collection of documents for the history of parapsychology, psychical research, spiritualism, and occultism – they are also taking steps to digitize some of their holdings. The digitized collection so far contains the most important occult, spiritualist, and parapsychological journals and periodicals in Germany. It is an excellent resource for the history of esotericism in the German speaking world from the late nineteenth century to the Second World War.

Levity is an online repository of alchemical texts, images, and commentary organized by independent scholar Adam McLean. It features tens of thousands of pages of text, over 3000 images, over 300 complete alchemical texts, extensive bibliographical material on the printed books and manuscripts, numerous articles, and introductory and general reference material on alchemy. In short, it is a very valuable place to start if you are looking for information on alchemy online.

The Internet Sacred Text Archive claims to possess the “largest freely available archive of online books about religion, mythology, folklore and the esoteric on the Internet.” It has collected a large number of “esoteric” source texts, ranging from translations of ancient material to documents that originally written in the digital era for the web.

The Twilit Grotto is run by the specialist of ritual magic, Joseph Peterson, and has slowly been building its archive since 1997. It offers a useful collection of primarily early modern and medieval prints and manuscripts (all in digital transcription). There is a strong predominance of magical material, clustering around the Solomonic grimoire tradition and Renaissance magical texts.

Electronic Journal dedicated to the critical historical study of alchemy

Alchemy, Magic and Kabbala (Foundation of the Works of C.G. Jung)

A useful resource for anyone interested in Newton’s alchemical manuscripts, plus articles and presentations.

A repertory of Ancient Astrological Works.

A fantastic collection of articles (in French) on all aspects of medieval history, including magic.