Swami teaches Classical Yoga its profound and progressive style; i.e., Karma, Bhakti, Raja (including Hatha) and Jnana Yoga. Swami empahsis that all of Yoga is, basically, the Hindu religion. Anyone can study, but only the Hindu (or, perhaps Buddhist, Jain or Sikh--religions that have evolved from Sanatan Dharma/Hinduism)can, ethically, teach. And, since all of Yoga is spiritual/religious/Hindu, Swami accepts only donations for his classes. He does offer publications through Inner Light Publishing. The philosophical aspect of the teachings come from Swami's book entitled: The Eternal Journey: A Guide To Enlightenment which he also offers as a correspondance course for those students who are unable to study with Swami personally.