While the reality of yoga history is that yoga has always evolved through the creative explorations and new experiences of those deeply into the practice, today there are tens of millions of people worldwide stepping onto yoga mats with some intention related to living a better life. On every continent, in nearly every culture, across the cycles of life and the patterns of gender, ethnicity, religion, and belief, we find people practicing yoga. In practicing yoga, people are making choices about their practice that are related to the other realities of their lives: where they are, their values, their immediate needs and goals. In the spirit of human endeavor to have greater clarity, meaning, and well-being in life, we find that people modify what they are learning from their teachers, books, and other sources. In some instances the modifications are designed to make the practice more accessible, as in the pioneering creativity of TiramulaiKrishnamacharya (who created Ashtanga Vinyasa...