What is “WTW?”

Yes, so, after literally years of searching for a website where authors could simply publish their own short works with ease, I found "Prose." However, in all of my searching (and my entire existence), I have never heard of anything with the acronym "WTW." However, here on this website I hear it referred to quite a bit, and it sounds like some sort of writing website. I have tried to look it up but can find no information on it whatsoever. I was simply wondering if anyone could give me some insight to this?...

Additionally, I have heard some pretty sorry things about it on "Prose." How come nobody seems to like it, and, furthermore, is it even worth my time? Thank you for taking the time to read this and for considering to answer my inquiry. All the best.