Well, I haven't checked the links you guys posted, but as far as I know, Tang Soo Do was the former name of TaeKwonDo. When the korean masters of Shotokan made a karate organisation in Korea they changed the name to its korean form - just as they did with Kendo, Judo etc. Then, when Tang Soo Do was modified into today's TKD, the name TaeKwonDo was voted most of all, because it was descriptive of the art and because it sounded a lot like Taek Kyon, and ancient street fighting korean martial art which was known for its kicks and cirular movement, and from which TKD takes it from. I dont know why TSD still exists - this is what i've learned from reading the history of TKD. according to this, TKD and TSD and the newer and older forms of the same art respectively. TSD looks a lot like shotokan because it was derived from it and it looks most like ITF TKD (the one Choi-Hong Hi founded) and less like WTF which was founded later as a public organisation in Korea (dont know if it was north or south). i could be wrong though