Islam
- 501
- Muhammad at-Taqi
- Profile of the Ninth Imam of the Twelver Shia tradition; from the Encyclopedia of the Orient.
- 502
- Musa al-Kazim
- Profile of the Seventh Imam in the Twelver Shia tradition; from the Encyclopedia of the Orient.
- 503
- Muhammad al Mahdi
- Profile of the Twelfth Imam, and beliefs about him; from the Encyclopedia of the Orient.
- 504
- Ali r-Rida
- Profile of the Eighth Imam in the Twelver Shia tradition; from the Encyclopedia of the Orient.
- 505
- Jafar as-Sadiq
- Profile of the Sixth Imam in the Twelver and Ismaili traditions; from the Encyclopedia of the Orient.
- 506
- Zayd ibn Ali
- Short article on Wikipedia; a profile of the son of the Fourth Shia Imam, believed by Zaidis to be the rightful successor.
- 507
- Ismail bin Jafar
- Profile from Wikipedia of the Seventh Imam in the Ismaili Shia tradition; the oldest son of Jafar as Sadiq.
- 508
- Ismail bin Jafar Sakik (148-158/765-775)
- Biography and context of the Seventh Imam according to the Ismaili tradition. Explores in detail the question of Ismail's succession from his father Jafar as Sadeq.
- 509
- Hassan
- Profile of the Second Imam, son of Ali and Fatima, grandson of the Prophet; from the Encyclopedia of the Orient.
- 510
- Husayn
- Profile of the Third Imam, second son of Ali and Fatima, grandson of the Prophet; died after the battle of Karbala. From the Encyclopedia of the Orient.
- 511
- Silsila Chishtia Sabria
- An account of the order, their teachers and genealogy, current organization, and activities. Also includes contact details.
- 512
- The Khanqae Chishtia Nizamia Habibia Soofia Qadiriyya
- Branch of the Chishti Nizamia Order based in Pietermaritzburg, South Africa; offers a collection of articles and writings, their history, and an events calendar.
- 513
- Halveti - Wikipedia, the free encyclopedia
- Hyperlinked article profiling this Sufi order (Khalwati in Arabic). [Wikipedia]
- 514
- Halveti-Jerrahi Order of Dervishes
- An international, traditional Sufi Order. Information about Sufism, their branches, and practical humanitarian work they have supported.
- 515
- International Mevlana Foundation, Switzerland
- Information about the Mevlevi order, their founder Rumi, and local activities.
- 517
- Mevlevi Order of America
- A history of the order in the US, and its roots in the teaching of Mevlana Jelaluddin Rumi (also known as the Whirling Dervishes). Includes information on their beliefs and practices, and an events listing.