It's a Firefox fork, optimised for different CPUs. I have the portable AMD x64 version and it's quick. It's very configurable (Worth the work figuring out how) and the Firefox add-ons I've installed all work faultlessly.
Thank you, I'll look into it.
What advantage over FF?
Speed, for one. Especially if you're running x64. Don't forget, too, that FF is going all Chrome on us, soon.
Similarities between this and Pale Moon. But, striking differences, too.