I think the idea in Fuchsia is that directories can be passed as resources to children processes, which can then move freely around in that directory structure.

I think the idea in Fuchsia is that directories can be passed as resources to children processes, which can then move freely around in that directory structure. If the parent passes a child "/foo/bar/", the child sees "bar/" and it's contents, which might be "bar/baz/bingo/". The child can then move to "/bar/baz/bingo/" do work there, and then recurse up the hierarchy. It simply cannot ".." out of "foo/". Hope that makes sense.