Ashtanga, or Power Yoga, is a system of Hatha Yoga developed by Sri K. Pattabhi Jois. It is distinguished by a very active, physical practice of the asanas, and is taught world-wide. Like most forms of Yoga, this system is based on eight-limbed ("ash-tanga") path described by Patanjali in the Yoga Sutras, but should not be confused with the Astanga Yoga that is a branch of Raja Yoga.