There's no second upper-case W. It's actually the
nom de guerre of a very old D&D character of mine who, when I recycled the character later as an NPC, could travel between worlds by opening a portal and stepping through it -- kind of handy for getting the players into all sorts of trouble.
It's not a very exciting name, I'm afraid, but it's been mine online since the early 1990s. Most of the other Worldwalkers aren't me, but some are (for those who were there, I'm the CI$ and Nexus one).