Lao Tzu or Laozi
Lao Tzu is a mythical figure and supposedly the author of Tao Te Ching.
He has been known as the first (though historically not proven) master of ancient Taoism. The Tao Te Ching, a brilliant non-dual teaching, has been attributed to Lao Tzu, but probably the text originates from various Chinese authors.
Over one hundred translations from the original Chinese version to English have been published, which are widely differing. I've chosen two contemporary versions for viewing (and download) here and a link with five more versions, among them my favorite translation by Stephen Mitchell: