Linux is not in the public domain. Linux is a cancer that attaches itself in an intellectual property sense to everything it touches. That's the way that the license works.
Bio: Erich Schiffmann is an accomplished American Yoga Master widely known for his award-winning video, Yoga Mind & Body, featuring actress Ali MacGraw. He is the author of a best-selling book, Moving into Stillness. He has been teaching yoga for more than twenty years.