What a wonderful post. It was perfect for me. Thank you , I had no idea that hatha yoga was an umbrella term encompassing (or the root of) other styles of yoga! I really appreciated the history outline, what is known of it, and references to the Marahabata and the Bhagvad Gita both of which I am inspired to re-read.
There is no time like the present, no time like any other.
...of the self through the self to the self...
Off I go. Farewell to all.
Peace and blessings
RE: Yoga 2.0 -- A User Guide for Getting Started