William Cathcart's Essays.
- A Baptist view of Gnostics, Dualists and others regarded as proto-Protestants. As well as Cathars ("Albigensians"), he discusses Novatianists, Donatists, Henricians, Petrobrussians and Anabaptists.
- http://www.21tnt.com/cathcartessays.htm#albigenses

The Great Mysteries of the Languedoc
- Legends and theories concerning the Cathars of the Languedoc and their alleged links to Rennes-le-Chateau, the Knights Templar, the Holy Grail, the Ark of the Covenant, and the Da Vinci Code.
- http://www.cathar.info/

Cathars of the Languedoc
- Catharism and its relationship to Dualism, Gnosticism and the Languedoc.
- http://www.cathar.info/cathars.htm

Cathars and the Kabbalah
- A distinctive forms of medieval kabbalism which had its birth or rather rebirth in the area of the Languedoc.
- http://www.orderofthegrail.org/cathars_and_the_kabala.htm

Cathars (Carthari) regarded as heretics
- An account of Catharism from a mainstream Christian point of view, from an internet Resource for Studying the Church in the Middles Ages.
- http://www.medievalchurch.org.uk/h_cathari.html

Bulgarian Bogomil and Apocryphal Ideas in Medieval English Culture
- Bogomil or proto-Cathar ideas.
- http://www.cl.bas.bg/Balkan-Studies/bogomilism/SummaryE.html

The Albigenses
- Text from the Catholic Encyclopedia about what the Roman Catholic Church regards as a neo-Manichean sect: the Cathars who flourished in what is now southern France in the twelfth and thirteenth centuries.
- http://www.newadvent.org/cathen/01267e.htm

Montsegur and the Cathar Heresy
- Introductuion to the Cathar faith. The significance of events at Montsegur during the Cathar period, including the names, where known, of the Cathars burned alive there. References to primary source material.
- http://www.russianbooks.org/montsegur.htm

Albigensian Crusade: Cathars and Catharism in the Languedoc
- Catharism in the Languedoc, Cathar beliefs. Cathars and heretics, the high culture of the troubadours and the Counts of Toulouse. The Role of the Roman Catholic Church: Innocent III, Crusades (The Albigensian Crusade) and the annexation of the Languedoc
- http://www.languedoc-france.info/12_cathars.htm

Worldwide Assembly of Good Christians
- Revival of the ancient Cathar faith and practice.
- http://www.cathar.net

Journey to the Land of Oc
- Offers detailed information and pictures about Cathar lands, the Albigensian Crusade, as well as the Cathar faith.
- http://www.cathars.org