Hatha yoga are two forms of hatha yoga: one practiced by Yajñavalkya consisting of the eight limbs of ashtanga yoga and another practiced by Kapila consisting of eight mudras. Currently, the oldest dated text to describe hatha yoga, the 11th century CE "Amṛtasiddhi", comes from a tantric Buddhist milieu. The oldest texts to use the actual verbiage of "hatha" are also Vajrayana Buddhist. In the 20th century, hatha yoga, particularly asanas (the physical postures), became popular throughout the world as a form of physical exercise, and is now colloquially termed simply as "yoga." According to the Indologist James Mallinson, some Hatha Yoga
Ashtanga vinyasa yoga and never taught by Sharath. However most of his teachers who claim to have been taught by him will teach the above methods, exercises, & postures, even though none of what they teach is part of the Ashtanga method of instruction under Sharath. Pattabhi Jois also did not require students to independently drop back and come up from back bending before progressing to the 2nd series. Sharath changed the requirements, and has now made this mandatory. However, it is important to note that Pattabhi Jois was the founder of the system, and taught each of his original students differently, instructing