I don't think anyone's really begun tackling it. There's widespread agreement that Haiku should eventually support it, but I don't know that anyone's done any

I don't think anyone's really begun tackling it. There's widespread agreement that Haiku should eventually support it, but I don't know that anyone's done any effort to really move in that direction (with one pseudo-exception: Haiku does a better job than BeOS properly arranging the file system into user-specific v. machine-specific folders, which will help when they get there).